diff --git a/graalpython/com.oracle.graal.python.frozen/freeze_modules.py b/graalpython/com.oracle.graal.python.frozen/freeze_modules.py
index ce4e6c5c5e..929029f5b8 100644
--- a/graalpython/com.oracle.graal.python.frozen/freeze_modules.py
+++ b/graalpython/com.oracle.graal.python.frozen/freeze_modules.py
@@ -112,7 +112,6 @@ def add_graalpython_core():
     l = []
     l.append("polyglot.arrow : polyglot.arrow = " + os.path.join(lib_graalpython, "modules/_polyglot_arrow.py"))
     for name in [
-        "modules/_sysconfigdata",
         "modules/_polyglot",
         "modules/_polyglot_time",
     ]:
diff --git a/graalpython/com.oracle.graal.python.resources/src/com/oracle/graal/python/resources/PythonResource.java b/graalpython/com.oracle.graal.python.resources/src/com/oracle/graal/python/resources/PythonResource.java
index 3894c908ce..4b76ac03e2 100644
--- a/graalpython/com.oracle.graal.python.resources/src/com/oracle/graal/python/resources/PythonResource.java
+++ b/graalpython/com.oracle.graal.python.resources/src/com/oracle/graal/python/resources/PythonResource.java
@@ -43,6 +43,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.InvalidPathException;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -66,6 +67,7 @@ public final class PythonResource implements InternalResource {
     private static final int PYTHON_MINOR;
     private static final int GRAALVM_MAJOR;
     private static final int GRAALVM_MINOR;
+    private static final String PYTHON_ABIFLAGS;
 
     /**
      * The version generated at build time is stored in an ASCII-compatible way. Add build time, we
@@ -82,6 +84,13 @@ public final class PythonResource implements InternalResource {
             is.read(); // skip python micro version
             GRAALVM_MAJOR = is.read() - VERSION_BASE;
             GRAALVM_MINOR = is.read() - VERSION_BASE;
+            is.read(); // skip GraalVM micro version
+            is.read(); // skip release level
+            int ch;
+            while ((ch = is.read()) != '\n' && ch != -1) {
+                // skip ABI version
+            }
+            PYTHON_ABIFLAGS = ch == -1 ? "" : new String(is.readAllBytes(), StandardCharsets.US_ASCII).strip();
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
@@ -117,7 +126,7 @@ public void unpackFiles(Env env, Path targetDirectory) throws IOException {
             env.unpackResourceFiles(BASE_PATH.resolve(LIBPYTHON_FILES), targetDirectory.resolve("lib").resolve(pythonMajMin), BASE_PATH.resolve(LIBPYTHON), filter);
             env.unpackResourceFiles(BASE_PATH.resolve(LIBGRAALPY_FILES), targetDirectory.resolve("lib").resolve("graalpy" + GRAALVM_MAJOR + "." + GRAALVM_MINOR), BASE_PATH.resolve(LIBGRAALPY),
                             filter);
-            env.unpackResourceFiles(BASE_PATH.resolve(INCLUDE_FILES), targetDirectory.resolve("include").resolve(pythonMajMin), BASE_PATH.resolve(INCLUDE), filter);
+            env.unpackResourceFiles(BASE_PATH.resolve(INCLUDE_FILES), targetDirectory.resolve("include").resolve(pythonMajMin + PYTHON_ABIFLAGS), BASE_PATH.resolve(INCLUDE), filter);
         }
         // ni files are in the same place on all platforms
         env.unpackResourceFiles(BASE_PATH.resolve(NI_FILES), targetDirectory, BASE_PATH, filter);
diff --git a/graalpython/com.oracle.graal.python.test/src/tests/test_sysconfig.py b/graalpython/com.oracle.graal.python.test/src/tests/test_sysconfig.py
index fd9e01898e..a3fab2f075 100644
--- a/graalpython/com.oracle.graal.python.test/src/tests/test_sysconfig.py
+++ b/graalpython/com.oracle.graal.python.test/src/tests/test_sysconfig.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # The Universal Permissive License (UPL), Version 1.0
@@ -47,7 +47,12 @@ def test_sysconfig():
     # must not fail
 
 
-@unittest.skipIf(sys.implementation.name != 'graalpy', "GraalPy-only test")
-def test_sysconfigdata():
-    # Maturin loads this directly, make sure the import works
-    import _sysconfigdata
+def test_platform_sysconfigdata():
+    import importlib
+    import sysconfig
+    mod = importlib.import_module(sysconfig._get_sysconfigdata_name())
+    # These flags are parsed directly from the file by maturin
+    for key in ("ABIFLAGS", "EXT_SUFFIX", "SOABI", "VERSION"):
+        assert key in mod.build_time_vars
+    assert mod.build_time_vars["ABIFLAGS"] == sys.abiflags
+    assert sys.abiflags in sysconfig.get_config_var("INCLUDEPY")
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java
index 22a4e70942..f1e831c942 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java
@@ -203,6 +203,7 @@ public final class PythonLanguage extends TruffleLanguage<PythonContext> {
 
     /** See {@code mx_graalpython.py:abi_version} */
     public static final String GRAALPY_ABI_VERSION;
+    public static final String GRAALPY_ABIFLAGS;
 
     /* Magic number used to mark pyc files */
     public static final int MAGIC_NUMBER = 21000 + Compiler.BYTECODE_VERSION * 10;
@@ -252,7 +253,9 @@ public final class PythonLanguage extends TruffleLanguage<PythonContext> {
                 default:
                     RELEASE_LEVEL_STRING = tsLiteral("final");
             }
-            GRAALPY_ABI_VERSION = new String(is.readAllBytes(), StandardCharsets.US_ASCII).strip();
+            String[] abiParts = new String(is.readAllBytes(), StandardCharsets.US_ASCII).split("\\R", 2);
+            GRAALPY_ABI_VERSION = abiParts[0].strip();
+            GRAALPY_ABIFLAGS = abiParts.length > 1 ? abiParts[1].strip() : "";
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java
index 8e3b59e649..71b23f763d 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java
@@ -288,6 +288,7 @@ public final class SysModuleBuiltins extends PythonBuiltins {
 
     public static final TruffleString T_CACHE_TAG = tsLiteral("cache_tag");
     public static final TruffleString T__MULTIARCH = tsLiteral("_multiarch");
+    public static final TruffleString T_ABIFLAGS = tsLiteral("abiflags");
 
     static {
         String compile_time;
@@ -497,7 +498,7 @@ public void initialize(Python3Core core) {
         StructSequence.initType(core, THREAD_INFO_DESC);
         StructSequence.initType(core, UNRAISABLEHOOK_ARGS_DESC);
 
-        addBuiltinConstant("abiflags", T_EMPTY_STRING);
+        addBuiltinConstant(T_ABIFLAGS, toTruffleStringUncached(PythonLanguage.GRAALPY_ABIFLAGS));
         addBuiltinConstant("byteorder", ByteOrder.nativeOrder() == ByteOrder.LITTLE_ENDIAN ? T_LITTLE : T_BIG);
         addBuiltinConstant("copyright", T_LICENSE);
         addBuiltinConstant(T_MODULES, PFactory.createDict(language));
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/module/FrozenModules.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/module/FrozenModules.java
index 8c7d926a52..c91a96b6a1 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/module/FrozenModules.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/module/FrozenModules.java
@@ -96,7 +96,6 @@ private static final class Map {
         private static final PythonFrozenModule __PHELLO___SPAM = new PythonFrozenModule("__PHELLO___SPAM", "__phello__.spam", false);
         private static final PythonFrozenModule FROZEN_ONLY = new PythonFrozenModule("FROZEN_ONLY", null, false);
         private static final PythonFrozenModule POLYGLOT_ARROW = new PythonFrozenModule("POLYGLOT_ARROW", null, false);
-        private static final PythonFrozenModule _SYSCONFIGDATA = new PythonFrozenModule("_SYSCONFIGDATA", null, false);
         private static final PythonFrozenModule _POLYGLOT = new PythonFrozenModule("_POLYGLOT", null, false);
         private static final PythonFrozenModule _POLYGLOT_TIME = new PythonFrozenModule("_POLYGLOT_TIME", null, false);
         private static final PythonFrozenModule GRAALPY___GRAALPYTHON__ = new PythonFrozenModule("GRAALPY___GRAALPYTHON__", null, false);
@@ -223,8 +222,6 @@ public static final PythonFrozenModule lookup(String name) {
                 return Map.FROZEN_ONLY;
             case "polyglot.arrow":
                 return Map.POLYGLOT_ARROW;
-            case "_sysconfigdata":
-                return Map._SYSCONFIGDATA;
             case "_polyglot":
                 return Map._POLYGLOT;
             case "_polyglot_time":
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonContext.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonContext.java
index 0ed9c6099d..b82c5e4b59 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonContext.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonContext.java
@@ -30,6 +30,7 @@
 import static com.oracle.graal.python.annotations.PythonOS.PLATFORM_DARWIN;
 import static com.oracle.graal.python.annotations.PythonOS.PLATFORM_WIN32;
 import static com.oracle.graal.python.builtins.PythonBuiltinClassType.SystemError;
+import static com.oracle.graal.python.builtins.modules.SysModuleBuiltins.T_ABIFLAGS;
 import static com.oracle.graal.python.builtins.modules.SysModuleBuiltins.T_CACHE_TAG;
 import static com.oracle.graal.python.builtins.modules.SysModuleBuiltins.T__MULTIARCH;
 import static com.oracle.graal.python.builtins.modules.io.IONodes.T_CLOSED;
@@ -2918,6 +2919,7 @@ public TruffleString getSoAbi() {
             Object implementationObj = ReadAttributeFromModuleNode.getUncached().execute(sysModule, T_IMPLEMENTATION);
             // sys.implementation.cache_tag
             TruffleString cacheTag = (TruffleString) PyObjectGetAttr.executeUncached(implementationObj, T_CACHE_TAG);
+            TruffleString abiFlags = (TruffleString) ReadAttributeFromModuleNode.getUncached().execute(sysModule, T_ABIFLAGS);
             // sys.implementation._multiarch
             TruffleString multiArch = (TruffleString) PyObjectGetAttr.executeUncached(implementationObj, T__MULTIARCH);
 
@@ -2933,7 +2935,7 @@ public TruffleString getSoAbi() {
                 soExt = T_EXT_SO;
             }
 
-            soABI = cat(T_DOT, cacheTag, T_DASH, T_NATIVE, T_DASH, multiArch, soExt);
+            soABI = cat(T_DOT, cacheTag, abiFlags, T_DASH, T_NATIVE, T_DASH, multiArch, soExt);
         }
         return soABI;
     }
diff --git a/graalpython/graalpy-pyconfig/CMakeLists.txt b/graalpython/graalpy-pyconfig/CMakeLists.txt
index 10c3448c73..ee79c2f64f 100644
--- a/graalpython/graalpy-pyconfig/CMakeLists.txt
+++ b/graalpython/graalpy-pyconfig/CMakeLists.txt
@@ -33,6 +33,23 @@ include(CheckSymbolExists)
 include(CheckIncludeFile)
 include (TestBigEndian)
 
+if(NOT DEFINED GRAALPY_SYSCONFIGDATA_NAME)
+    if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+        set(GRAALPY_SYSCONFIG_PLATFORM "darwin")
+    elseif(CMAKE_SYSTEM_NAME STREQUAL "Windows")
+        set(GRAALPY_SYSCONFIG_PLATFORM "win32")
+    else()
+        set(GRAALPY_SYSCONFIG_PLATFORM "linux")
+    endif()
+
+    string(TOLOWER "${CMAKE_SYSTEM_PROCESSOR}" GRAALPY_SYSCONFIG_ARCH)
+    if(GRAALPY_SYSCONFIG_ARCH STREQUAL "amd64")
+        set(GRAALPY_SYSCONFIG_ARCH "x86_64")
+    endif()
+    set(GRAALPY_SYSCONFIG_MULTIARCH "${GRAALPY_SYSCONFIG_ARCH}-${GRAALPY_SYSCONFIG_PLATFORM}")
+    set(GRAALPY_SYSCONFIGDATA_NAME "_sysconfigdata__${GRAALPY_SYSCONFIG_PLATFORM}_${GRAALPY_SYSCONFIG_MULTIARCH}")
+endif()
+
 test_big_endian(IS_BIG_ENDIAN)
 
 set(CMAKE_REQUIRED_LINK_OPTIONS "-lm")
@@ -70,4 +87,99 @@ else()
     set(DOUBLE_IS_LITTLE_ENDIAN_IEEE754 1)
 endif()
 
+function(graalpy_sysconfig_value name default_value)
+    if(DEFINED ENV{GRAALPY_SYSCONFIG_${name}})
+        set(GRAALPY_SYSCONFIG_${name} "$ENV{GRAALPY_SYSCONFIG_${name}}" PARENT_SCOPE)
+    else()
+        set(GRAALPY_SYSCONFIG_${name} "${default_value}" PARENT_SCOPE)
+    endif()
+endfunction()
+
+function(graalpy_sysconfig_empty name)
+    graalpy_sysconfig_value("${name}" "")
+endfunction()
+
+function(graalpy_sysconfig_env_value name)
+    if(DEFINED ENV{GRAALPY_SYSCONFIG_${name}})
+        set(GRAALPY_SYSCONFIG_${name} "$ENV{GRAALPY_SYSCONFIG_${name}}" PARENT_SCOPE)
+    else()
+        set(GRAALPY_SYSCONFIG_${name} "" PARENT_SCOPE)
+    endif()
+endfunction()
+
+function(graalpy_sysconfig_python_string name)
+    set(value "${${name}}")
+    string(REPLACE "\\" "\\\\" value "${value}")
+    string(REPLACE "\"" "\\\"" value "${value}")
+    string(REPLACE "\n" "\\n" value "${value}")
+    string(REPLACE "\r" "\\r" value "${value}")
+    set(${name}_PYTHON_STRING "${value}" PARENT_SCOPE)
+endfunction()
+
+graalpy_sysconfig_value("OPT" "-DNDEBUG")
+graalpy_sysconfig_value("ARFLAGS" "rc")
+graalpy_sysconfig_value("USE_GNU_SOURCE" "-D_GNU_SOURCE=1")
+set(GRAALPY_SYSCONFIG_CFLAGS_DEFAULT_VALUE "${GRAALPY_SYSCONFIG_OPT}")
+if(WIN32)
+    set(GRAALPY_SYSCONFIG_CFLAGS_DEFAULT_VALUE "${GRAALPY_SYSCONFIG_CFLAGS_DEFAULT_VALUE} -DMS_WINDOWS -DPy_ENABLE_SHARED -DHAVE_DECLSPEC_DLL")
+endif()
+graalpy_sysconfig_value("CFLAGS_DEFAULT" "${GRAALPY_SYSCONFIG_CFLAGS_DEFAULT_VALUE}")
+graalpy_sysconfig_value("CFLAGS" "${GRAALPY_SYSCONFIG_CFLAGS_DEFAULT} ${GRAALPY_SYSCONFIG_USE_GNU_SOURCE}")
+graalpy_sysconfig_env_value("AR")
+graalpy_sysconfig_env_value("CC")
+graalpy_sysconfig_env_value("CXX")
+graalpy_sysconfig_env_value("LD")
+graalpy_sysconfig_env_value("NM")
+graalpy_sysconfig_env_value("RANLIB")
+if(APPLE)
+    graalpy_sysconfig_value("LDFLAGS" "-bundle -undefined dynamic_lookup")
+    graalpy_sysconfig_value("MACOSX_DEPLOYMENT_TARGET" "11")
+else()
+    graalpy_sysconfig_empty("LDFLAGS")
+    graalpy_sysconfig_empty("MACOSX_DEPLOYMENT_TARGET")
+endif()
+if(WIN32)
+    graalpy_sysconfig_empty("CCSHARED")
+    graalpy_sysconfig_value("SHLIB_SUFFIX" ".pyd")
+    graalpy_sysconfig_value("EXE" ".exe")
+else()
+    graalpy_sysconfig_value("CCSHARED" "-fPIC")
+    graalpy_sysconfig_value("SHLIB_SUFFIX" ".so")
+    graalpy_sysconfig_empty("EXE")
+endif()
+graalpy_sysconfig_env_value("LDCXXSHARED")
+graalpy_sysconfig_env_value("LDSHARED")
+graalpy_sysconfig_value("LDLIBRARY" "libpython.${GRAALPY_SYSCONFIG_SOABI}${GRAALPY_SYSCONFIG_SHLIB_SUFFIX}")
+
+set(GRAALPY_SYSCONFIG_STRING_NAMES
+    ABIFLAGS
+    AR
+    ARFLAGS
+    CC
+    CCSHARED
+    CFLAGS
+    CFLAGS_DEFAULT
+    CXX
+    EXE
+    EXT_SUFFIX
+    LD
+    LDCXXSHARED
+    LDLIBRARY
+    LDFLAGS
+    LDSHARED
+    MACOSX_DEPLOYMENT_TARGET
+    MULTIARCH
+    NM
+    OPT
+    RANLIB
+    SHLIB_SUFFIX
+    SOABI
+    USE_GNU_SOURCE
+    VERSION
+)
+foreach(name IN LISTS GRAALPY_SYSCONFIG_STRING_NAMES)
+    graalpy_sysconfig_python_string("GRAALPY_SYSCONFIG_${name}")
+endforeach()
+
 configure_file("pyconfig_template.h" "pyconfig.h" @ONLY)
+configure_file("_sysconfigdata_template.py" "${GRAALPY_SYSCONFIGDATA_NAME}.py" @ONLY)
diff --git a/graalpython/graalpy-pyconfig/_sysconfigdata_template.py b/graalpython/graalpy-pyconfig/_sysconfigdata_template.py
new file mode 100644
index 0000000000..7db9c37367
--- /dev/null
+++ b/graalpython/graalpy-pyconfig/_sysconfigdata_template.py
@@ -0,0 +1,80 @@
+# Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# The Universal Permissive License (UPL), Version 1.0
+#
+# Subject to the condition set forth below, permission is hereby granted to any
+# person obtaining a copy of this software, associated documentation and/or
+# data (collectively the "Software"), free of charge and under any and all
+# copyright rights in the Software, and any and all patent rights owned or
+# freely licensable by each licensor hereunder covering either (i) the
+# unmodified Software as contributed to or provided by such licensor, or (ii)
+# the Larger Works (as defined below), to deal in both
+#
+# (a) the Software, and
+#
+# (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
+# one is included with the Software each a "Larger Work" to which the Software
+# is contributed by such licensors),
+#
+# without restriction, including without limitation the rights to copy, create
+# derivative works of, display, perform, and distribute the Software and make,
+# use, sell, offer for sale, import, export, have made, and have sold the
+# Software and the Larger Work(s), and to sublicense the foregoing rights on
+# either these or other terms.
+#
+# This license is subject to the following condition:
+#
+# The above copyright notice and either this complete permission notice or at a
+# minimum a reference to the UPL must be included in all copies or substantial
+# portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# system configuration generated and used by the sysconfig module
+
+build_time_vars = {
+    "ABIFLAGS": "@GRAALPY_SYSCONFIG_ABIFLAGS_PYTHON_STRING@",
+    "ARFLAGS": "@GRAALPY_SYSCONFIG_ARFLAGS_PYTHON_STRING@",
+    "CCSHARED": "@GRAALPY_SYSCONFIG_CCSHARED_PYTHON_STRING@",
+    "CFLAGS": "@GRAALPY_SYSCONFIG_CFLAGS_PYTHON_STRING@",
+    "CFLAGS_DEFAULT": "@GRAALPY_SYSCONFIG_CFLAGS_DEFAULT_PYTHON_STRING@",
+    "EXE": "@GRAALPY_SYSCONFIG_EXE_PYTHON_STRING@",
+    "EXT_SUFFIX": "@GRAALPY_SYSCONFIG_EXT_SUFFIX_PYTHON_STRING@",
+    "LDLIBRARY": "@GRAALPY_SYSCONFIG_LDLIBRARY_PYTHON_STRING@",
+    "LDFLAGS": "@GRAALPY_SYSCONFIG_LDFLAGS_PYTHON_STRING@",
+    "LIBPYTHON": "",
+    "LIBS": "",
+    "MACOSX_DEPLOYMENT_TARGET": "@GRAALPY_SYSCONFIG_MACOSX_DEPLOYMENT_TARGET_PYTHON_STRING@",
+    "MULTIARCH": "@GRAALPY_SYSCONFIG_MULTIARCH_PYTHON_STRING@",
+    "OPT": "@GRAALPY_SYSCONFIG_OPT_PYTHON_STRING@",
+    "Py_GIL_DISABLED": @GRAALPY_SYSCONFIG_GIL_DISABLED@,
+    "Py_DEBUG": 0,
+    "Py_ENABLE_SHARED": 0,
+    "Py_HASH_ALGORITHM": 0,
+    "SHLIB_SUFFIX": "@GRAALPY_SYSCONFIG_SHLIB_SUFFIX_PYTHON_STRING@",
+    "SO": "@GRAALPY_SYSCONFIG_EXT_SUFFIX_PYTHON_STRING@",
+    "SOABI": "@GRAALPY_SYSCONFIG_SOABI_PYTHON_STRING@",
+    "SYSLIBS": "",
+    "USE_GNU_SOURCE": "@GRAALPY_SYSCONFIG_USE_GNU_SOURCE_PYTHON_STRING@",
+    "VERSION": "@GRAALPY_SYSCONFIG_VERSION_PYTHON_STRING@",
+}
+
+for _key, _value in {
+    "AR": "@GRAALPY_SYSCONFIG_AR_PYTHON_STRING@",
+    "CC": "@GRAALPY_SYSCONFIG_CC_PYTHON_STRING@",
+    "CXX": "@GRAALPY_SYSCONFIG_CXX_PYTHON_STRING@",
+    "LD": "@GRAALPY_SYSCONFIG_LD_PYTHON_STRING@",
+    "LDCXXSHARED": "@GRAALPY_SYSCONFIG_LDCXXSHARED_PYTHON_STRING@",
+    "LDSHARED": "@GRAALPY_SYSCONFIG_LDSHARED_PYTHON_STRING@",
+    "NM": "@GRAALPY_SYSCONFIG_NM_PYTHON_STRING@",
+    "RANLIB": "@GRAALPY_SYSCONFIG_RANLIB_PYTHON_STRING@",
+}.items():
+    if _value:
+        build_time_vars[_key] = _value
diff --git a/graalpython/graalpy-versions/CMakeLists.txt b/graalpython/graalpy-versions/CMakeLists.txt
index aff3acc34c..a2ba93cafe 100644
--- a/graalpython/graalpy-versions/CMakeLists.txt
+++ b/graalpython/graalpy-versions/CMakeLists.txt
@@ -32,8 +32,11 @@ project(graalpy-versions LANGUAGES NONE)
 if (NOT DEFINED GRAALPY_VER)
     message(FATAL_ERROR "GRAALPY_VER needs to be set")
 endif()
+if (NOT DEFINED GRAALPY_ABIFLAGS)
+    set(GRAALPY_ABIFLAGS "")
+endif()
 
 # Generates file 'graalpy_versions' with the given content.
 # The file will be created if it does not exist and will only be updated if the
 # content changes.
-file(GENERATE OUTPUT "graalpy_versions" CONTENT "${GRAALPY_VER}")
+file(GENERATE OUTPUT "graalpy_versions" CONTENT "${GRAALPY_VER}\n${GRAALPY_ABIFLAGS}")
diff --git a/graalpython/lib-graalpython/_sysconfig.py b/graalpython/lib-graalpython/_sysconfig.py
index 15e55419d1..992fd3f3d1 100644
--- a/graalpython/lib-graalpython/_sysconfig.py
+++ b/graalpython/lib-graalpython/_sysconfig.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # The Universal Permissive License (UPL), Version 1.0
@@ -38,27 +38,32 @@
 # SOFTWARE.
 
 
-def _get_posix_vars():
-    """Initialize the config vars as appropriate for POSIX systems."""
-    import _imp
-    import sys
+def _append_flags(g, key, flags):
+    value = g.get(key, "")
+    parts = value.split()
+    for flag in flags:
+        if flag and flag not in parts:
+            parts.append(flag)
+    g[key] = " ".join(parts)
+
+
+def _setdefault(g, key, value):
+    if key not in g:
+        g[key] = value
+
+
+def _update_posix_vars(config_vars=None):
+    """Add runtime path-dependent config vars."""
     import os
-    darwin_native = sys.platform == "darwin"
-    win32_native = sys.platform == "win32"
+    import sys
 
-    # note: this must be kept in sync with _imp.extension_suffixes
-    so_abi = sys.implementation.cache_tag + "-native-" + sys.implementation._multiarch
-    if win32_native:
-        so_ext = ".pyd"
-    else:
-        so_ext = ".so"
-    assert _imp.extension_suffixes()[0] == "." + so_abi + so_ext, "mismatch between extension suffix to _imp.extension_suffixes"
+    if config_vars is None:
+        config_vars = {}
 
+    win32_native = sys.platform == "win32"
+    darwin_native = sys.platform == "darwin"
     get_toolchain = __graalpython__.determine_system_toolchain().get
 
-    toolchain_cxx = get_toolchain('CXX')
-    have_cxx = toolchain_cxx is not None
-
     if win32_native:
         python_inc = os.path.join(os.path.normpath(sys.base_prefix), 'Include')
     else:
@@ -68,84 +73,30 @@ def _get_posix_vars():
             f'python{sys.version_info[0]}.{sys.version_info[1]}{sys.abiflags}'
         )
 
-    fpic = "" if win32_native else "-fPIC"
-
-    g = {}
-    g['CC'] = get_toolchain('CC')
-    g['CXX'] = toolchain_cxx if have_cxx else get_toolchain('CC') + ' --driver-mode=g++'
-    opt_flags = ["-DNDEBUG"]
-    g['OPT'] = ' '.join(opt_flags)
-    g['INCLUDEPY'] = python_inc
-    g['CONFINCLUDEPY'] = python_inc
-    g['CPPFLAGS'] = '-I. -I' + python_inc
-    gnu_source = "-D_GNU_SOURCE=1"
-    g['USE_GNU_SOURCE'] = gnu_source
-    cflags_default = list(opt_flags)
+    _setdefault(config_vars, 'CC', get_toolchain('CC'))
+    _setdefault(config_vars, 'CXX', get_toolchain('CXX'))
+    _setdefault(config_vars, 'AR', get_toolchain('AR'))
+    _setdefault(config_vars, 'RANLIB', get_toolchain('RANLIB'))
+    _setdefault(config_vars, 'LD', get_toolchain('LD'))
+    _setdefault(config_vars, 'NM', get_toolchain('NM'))
+    _setdefault(config_vars, 'INCLUDEPY', python_inc)
+    _setdefault(config_vars, 'CONFINCLUDEPY', python_inc)
+    _append_flags(config_vars, 'CPPFLAGS', ['-I.', '-I' + python_inc])
     if win32_native:
-        cflags_default += ["-DMS_WINDOWS", "-DPy_ENABLE_SHARED", "-DHAVE_DECLSPEC_DLL"]
-    g['CFLAGS_DEFAULT'] = ' '.join(cflags_default)
-    g['CFLAGS'] = ' '.join(cflags_default + [gnu_source])
-    g['LDFLAGS'] = ""
-    g['LIBS'] = ""
-    g['SYSLIBS'] = ""
-    g['CCSHARED'] = fpic
-    if darwin_native:
-        # MACOSX_DEPLOYMENT_TARGET is taken from the minimum version we build
-        # GraalPy for, which is currently BigSur
-        g['MACOSX_DEPLOYMENT_TARGET'] = "11"
-    else:
-        g['MACOSX_DEPLOYMENT_TARGET'] = ""
-    if darwin_native:
-        g['LDFLAGS'] = "-bundle -undefined dynamic_lookup"
-        ldshared_common = g['LDFLAGS']
-        g['LIBPYTHON'] = ''
-    elif win32_native:
-        g['LDFLAGS'] = f"-L{__graalpython__.capi_home.replace(os.path.sep, '/')}"
-        ldshared_common = f"-shared {fpic} {g['LDFLAGS']}"
+        lib_path = f"-L{__graalpython__.capi_home.replace(os.path.sep, '/')}"
+        _append_flags(config_vars, 'LDFLAGS', [lib_path])
+        if 'LDSHARED' in config_vars:
+            _append_flags(config_vars, 'LDSHARED', [lib_path])
+        if 'LDCXXSHARED' in config_vars:
+            _append_flags(config_vars, 'LDCXXSHARED', [lib_path])
+        ldshared_common = f"-shared {config_vars.get('CCSHARED', '')} {config_vars.get('LDFLAGS', '')}"
+    elif darwin_native:
+        ldshared_common = config_vars.get('LDFLAGS', '')
     else:
-        ldshared_common = f"-shared {fpic}"
-        g['LIBPYTHON'] = ''
-    g['LDSHARED'] = f"{g['CC']} {ldshared_common}"
-    g['LDCXXSHARED'] = f"{g['CXX']} {ldshared_common}"
-    g['SOABI'] = so_abi
-    g['EXT_SUFFIX'] = "." + so_abi + so_ext
-    g['SHLIB_SUFFIX'] = so_ext
-    g['SO'] = "." + so_abi + so_ext # deprecated in Python 3, for backward compatibility
-    g['AR'] = get_toolchain('AR')
-    g['RANLIB'] = get_toolchain('RANLIB')
-    g['ARFLAGS'] = "rc"
-    g['LD'] = get_toolchain('LD')
-    g['EXE'] = ".exe" if win32_native else ""
-    g['LIBDIR'] = os.path.join(sys.prefix, 'lib')
-    g['VERSION'] = ".".join(sys.version.split(".")[:2])
-    g['Py_HASH_ALGORITHM'] = 0 # does not give any specific info about the hashing algorithm
-    g['NM'] = get_toolchain('NM')
-    g['MULTIARCH'] = sys.implementation._multiarch
-    g['ABIFLAGS'] = ""
-    g['Py_DEBUG'] = 0
-    g['Py_ENABLE_SHARED'] = 0
-    g['LIBDIR'] = __graalpython__.capi_home
-    g['LIBDEST'] = __graalpython__.capi_home
-    g['LDLIBRARY'] = 'libpython.' + so_abi + so_ext
-    g['LIBPL'] = __graalpython__.capi_home.replace(os.path.sep, '/')
-    return g
-
-
-def make_sysconfigdata():
-    # the sysconfigdata module name matches what's computed in stdlib's sysconfig.py
-    import sys
-    multiarch = getattr(sys.implementation, '_multiarch', '')
-    name = f'_sysconfigdata_{sys.abiflags}_{sys.platform}_{multiarch}'
-    sys.modules[name] = mod = type(sys)(name)
-    no_default = object()
-    def __getattr__(key, default=no_default):
-        if key == "build_time_vars":
-            return _get_posix_vars()
-        elif default is no_default:
-            raise AttributeError(key)
-        else:
-            return default
-    mod.__getattr__ = __getattr__
-
-
-make_sysconfigdata()
+        ldshared_common = f"-shared {config_vars.get('CCSHARED', '')}"
+    _setdefault(config_vars, 'LDSHARED', f"{config_vars['CC']} {ldshared_common}".rstrip())
+    _setdefault(config_vars, 'LDCXXSHARED', f"{config_vars['CXX']} {ldshared_common}".rstrip())
+    _setdefault(config_vars, 'LIBDIR', __graalpython__.capi_home)
+    _setdefault(config_vars, 'LIBDEST', __graalpython__.capi_home)
+    _setdefault(config_vars, 'LIBPL', __graalpython__.capi_home.replace(os.path.sep, '/'))
+    return config_vars
diff --git a/graalpython/lib-graalpython/modules/_sysconfigdata.py b/graalpython/lib-graalpython/modules/_sysconfigdata.py
deleted file mode 100644
index 1f1f5860a7..0000000000
--- a/graalpython/lib-graalpython/modules/_sysconfigdata.py
+++ /dev/null
@@ -1,43 +0,0 @@
-# Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
-# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
-#
-# The Universal Permissive License (UPL), Version 1.0
-#
-# Subject to the condition set forth below, permission is hereby granted to any
-# person obtaining a copy of this software, associated documentation and/or
-# data (collectively the "Software"), free of charge and under any and all
-# copyright rights in the Software, and any and all patent rights owned or
-# freely licensable by each licensor hereunder covering either (i) the
-# unmodified Software as contributed to or provided by such licensor, or (ii)
-# the Larger Works (as defined below), to deal in both
-#
-# (a) the Software, and
-#
-# (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
-# one is included with the Software each a "Larger Work" to which the Software
-# is contributed by such licensors),
-#
-# without restriction, including without limitation the rights to copy, create
-# derivative works of, display, perform, and distribute the Software and make,
-# use, sell, offer for sale, import, export, have made, and have sold the
-# Software and the Larger Work(s), and to sublicense the foregoing rights on
-# either these or other terms.
-#
-# This license is subject to the following condition:
-#
-# The above copyright notice and either this complete permission notice or at a
-# minimum a reference to the UPL must be included in all copies or substantial
-# portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-# SOFTWARE.
-
-
-from _sysconfig import _get_posix_vars
-
-build_time_vars = _get_posix_vars()
diff --git a/graalpython/lib-python/3/sysconfig.py b/graalpython/lib-python/3/sysconfig.py
index b1352ef0b8..4ccf80b2de 100644
--- a/graalpython/lib-python/3/sysconfig.py
+++ b/graalpython/lib-python/3/sysconfig.py
@@ -530,9 +530,16 @@ def _init_posix(vars):
     """Initialize the module as appropriate for POSIX systems."""
     # _sysconfigdata is generated at build time, see _generate_posix_vars()
     name = _get_sysconfigdata_name()
-    _temp = __import__(name, globals(), locals(), ['build_time_vars'], 0)
-    build_time_vars = _temp.build_time_vars
-    vars.update(build_time_vars)
+    # GraalPy change: ignore missing _sysconfigdata, it can happen on an unsupported platform
+    try:
+        _temp = __import__(name, globals(), locals(), ['build_time_vars'], 0)
+        build_time_vars = _temp.build_time_vars
+        vars.update(build_time_vars)
+    except ModuleNotFoundError as e:
+        pass
+    # GraalPy change: merge our runtime vars
+    import _sysconfig
+    _sysconfig._update_posix_vars(vars)
 
 def _init_non_posix(vars):
     """Initialize the module as appropriate for NT"""
diff --git a/mx.graalpython/mx_graalpython.py b/mx.graalpython/mx_graalpython.py
index 8392bc9d86..15089d12c2 100644
--- a/mx.graalpython/mx_graalpython.py
+++ b/mx.graalpython/mx_graalpython.py
@@ -91,6 +91,9 @@ def get_boolean_env(name, default=False):
 SUITE_COMPILER = mx.suite("compiler", fatalIfMissing=False)
 
 GRAALPY_ABI_VERSION = 'graalpy250'
+GRAALPY_ABIFLAGS = os.environ.get('GRAALPY_ABIFLAGS', '')
+if not re.fullmatch(r'[A-Za-z0-9_]*', GRAALPY_ABIFLAGS):
+    mx.abort('GRAALPY_ABIFLAGS may only contain ASCII letters, digits, and underscores')
 IS_RELEASE = SUITE.is_release()
 FULL_GRAAL_VERSION = SUITE.release_version()
 GRAAL_VERSION = FULL_GRAAL_VERSION if IS_RELEASE else FULL_GRAAL_VERSION[:-len('-dev')]
@@ -2060,23 +2063,50 @@ def graalpy_cmake_build_type(*_):
     return 'Debug' if 'GRAALPY_NATIVE_DEBUG_BUILD' in os.environ else 'Release'
 
 
-def graalpy_ext(*_):
-    os = mx_subst.path_substitutions.substitute('<os>')
+def _graalpy_sysconfig_platform(os):
+    if os == 'darwin':
+        return 'darwin'
+    if os == 'windows':
+        return 'win32'
+    return 'linux'
+
+
+def _graalpy_sysconfig_arch():
     arch = mx_subst.path_substitutions.substitute('<arch>')
     if arch == 'amd64':
         # be compatible with CPython's designation
         # (see also: 'PythonUtils.getPythonArch')
         arch = 'x86_64'
+    return arch
 
-    # 'pyos' also needs to be compatible with CPython's designation.
-    # See class 'com.oracle.graal.python.annotations.PythonOS'
-    # In this case, we can just use 'sys.platform' of the Python running MX.
-    pyos = sys.platform
 
+def graalpy_soabi(*_):
+    os = mx_subst.path_substitutions.substitute('<os>')
+    pyos = _graalpy_sysconfig_platform(os)
+    return f'{abi_version()}{graalpy_abiflags()}-native-{graalpy_multiarch(os=pyos)}'
+
+
+def graalpy_ext(*_):
+    os = mx_subst.path_substitutions.substitute('<os>')
     # on Windows we use '.pyd' else '.so' but never '.dylib' (similar to CPython):
     # https://github.com/python/cpython/issues/37510
     ext = 'pyd' if os == 'windows' else 'so'
-    return f'.{abi_version()}-native-{arch}-{pyos}.{ext}'
+    return f'.{graalpy_soabi()}.{ext}'
+
+
+def graalpy_sysconfigdata(*_):
+    os = mx_subst.path_substitutions.substitute('<os>')
+    pyos = _graalpy_sysconfig_platform(os)
+    return f'_sysconfigdata_{graalpy_abiflags()}_{pyos}_{graalpy_multiarch(os=pyos)}'
+
+
+def graalpy_multiarch(*_, os=None):
+    pyos = os if os is not None else _graalpy_sysconfig_platform(mx_subst.path_substitutions.substitute('<os>'))
+    return f'{_graalpy_sysconfig_arch()}-{pyos}'
+
+
+def graalpy_abiflags(*_):
+    return GRAALPY_ABIFLAGS
 
 
 def dev_tag(_=None):
@@ -2118,6 +2148,14 @@ def abi_version():
 
 mx_subst.path_substitutions.register_no_arg('graalpy_ext', graalpy_ext)
 mx_subst.results_substitutions.register_no_arg('graalpy_ext', graalpy_ext)
+mx_subst.path_substitutions.register_no_arg('graalpy_abiflags', graalpy_abiflags)
+mx_subst.results_substitutions.register_no_arg('graalpy_abiflags', graalpy_abiflags)
+mx_subst.path_substitutions.register_no_arg('graalpy_soabi', graalpy_soabi)
+mx_subst.results_substitutions.register_no_arg('graalpy_soabi', graalpy_soabi)
+mx_subst.path_substitutions.register_no_arg('graalpy_multiarch', graalpy_multiarch)
+mx_subst.results_substitutions.register_no_arg('graalpy_multiarch', graalpy_multiarch)
+mx_subst.path_substitutions.register_no_arg('graalpy_sysconfigdata', graalpy_sysconfigdata)
+mx_subst.results_substitutions.register_no_arg('graalpy_sysconfigdata', graalpy_sysconfigdata)
 
 mx_subst.results_substitutions.register_no_arg('graalpy_cmake_build_type', graalpy_cmake_build_type)
 mx_subst.string_substitutions.register_no_arg('bcflags', bcflags)
diff --git a/mx.graalpython/suite.py b/mx.graalpython/suite.py
index 8333b42226..9d32268b6c 100644
--- a/mx.graalpython/suite.py
+++ b/mx.graalpython/suite.py
@@ -652,6 +652,7 @@
             "ninja_targets": ["all"],
             "cmakeConfig": {
                 "GRAALPY_VER": "<py_ver:binary><graal_ver:binary><release_level:binary><abi_version>",
+                "GRAALPY_ABIFLAGS": "<graalpy_abiflags>",
             },
             "results": [
                 "graalpy_versions"
@@ -670,9 +671,17 @@
             "cmakeConfig": {
                 "GRAALPY_VERSION": "<graal_ver:default>",
                 "GRAALPY_VERSION_NUM": "<graal_ver:hex>",
+                "GRAALPY_SYSCONFIGDATA_NAME": "<graalpy_sysconfigdata>",
+                "GRAALPY_SYSCONFIG_ABIFLAGS": "<graalpy_abiflags>",
+                "GRAALPY_SYSCONFIG_EXT_SUFFIX": "<graalpy_ext>",
+                "GRAALPY_SYSCONFIG_GIL_DISABLED": "0",
+                "GRAALPY_SYSCONFIG_MULTIARCH": "<graalpy_multiarch>",
+                "GRAALPY_SYSCONFIG_SOABI": "<graalpy_soabi>",
+                "GRAALPY_SYSCONFIG_VERSION": "<py_ver:major_minor>",
             },
             "results": [
                 "pyconfig.h",
+                "<graalpy_sysconfigdata>.py",
             ],
         },
 
@@ -1339,6 +1348,7 @@
                             "./META-INF/resources/<os>/<arch>/Lib/venv/scripts/nt/graalpy.exe": "dependency:python-venvlauncher",
                             "./META-INF/resources/<os>/<arch>/Lib/venv/scripts/nt/python.exe": "dependency:python-venvlauncher",
                             "./META-INF/resources/<os>/<arch>/include/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/pyconfig.h",
+                            "./META-INF/resources/<os>/<arch>/lib-graalpython/modules/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/<graalpy_sysconfigdata>.py",
                         },
                     },
                 },
@@ -1349,7 +1359,8 @@
                                 "dependency:GRAALPYTHON_NATIVE_LIBS/<os>/<arch>/*",
                             ],
                             "./META-INF/resources/<os>/<arch>/lib/python<py_ver:major_minor>/venv/scripts/macos/graalpy": "dependency:python-macos-launcher",
-                            "./META-INF/resources/<os>/<arch>/include/python<py_ver:major_minor>/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/pyconfig.h",
+                            "./META-INF/resources/<os>/<arch>/include/python<py_ver:major_minor><graalpy_abiflags>/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/pyconfig.h",
+                            "./META-INF/resources/<os>/<arch>/lib/graalpy<graal_ver:major_minor>/modules/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/<graalpy_sysconfigdata>.py",
                         }
                     }
                 },
@@ -1359,7 +1370,8 @@
                             "./META-INF/resources/<os>/<arch>/lib/graalpy<graal_ver:major_minor>/": [
                                 "dependency:GRAALPYTHON_NATIVE_LIBS/<os>/<arch>/*",
                             ],
-                            "./META-INF/resources/<os>/<arch>/include/python<py_ver:major_minor>/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/pyconfig.h",
+                            "./META-INF/resources/<os>/<arch>/include/python<py_ver:major_minor><graalpy_abiflags>/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/pyconfig.h",
+                            "./META-INF/resources/<os>/<arch>/lib/graalpy<graal_ver:major_minor>/modules/": "dependency:graalpy-pyconfig/<os>-<arch>/<multitarget_libc_selection>/<graalpy_sysconfigdata>.py",
                         },
                     },
                 },
@@ -1424,7 +1436,7 @@
                             "./lib/graalpy<graal_ver:major_minor>/": [
                                 "dependency:GRAALPYTHON_LIBGRAALPY_RESOURCES/META-INF/resources/libgraalpy/*",
                             ],
-                            "./include/python<py_ver:major_minor>/": [
+                            "./include/python<py_ver:major_minor><graalpy_abiflags>/": [
                                 "dependency:GRAALPYTHON_INCLUDE_RESOURCES/META-INF/resources/include/*",
                             ],
                             "./": [