--- a/CMakeLists.txt	2025-08-02 22:16:37.819326103 +0200
+++ b/CMakeLists.txt	2025-08-02 22:23:45.495251935 +0200
@@ -531,10 +531,11 @@
 add_onnx_global_defines(onnx)
 
 if(ONNX_BUILD_PYTHON)
-  Python3_add_library(onnx_cpp2py_export MODULE WITH_SOABI "${ONNX_ROOT}/onnx/cpp2py_export.cc")
+  add_library(onnx_cpp2py_export MODULE "${ONNX_ROOT}/onnx/cpp2py_export.cc")
   set_target_properties(onnx_cpp2py_export PROPERTIES PREFIX "")
   set_target_properties(onnx_cpp2py_export PROPERTIES CXX_VISIBILITY_PRESET hidden)
   set_target_properties(onnx_cpp2py_export PROPERTIES VISIBILITY_INLINES_HIDDEN ON)
+  set_target_properties(onnx_cpp2py_export PROPERTIES SUFFIX ${PY_EXT_SUFFIX})
   set_target_properties(onnx_cpp2py_export
                         PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
   target_include_directories(onnx_cpp2py_export PRIVATE
--- a/setup.py	2025-08-02 22:16:43.509352511 +0200
+++ b/setup.py	2025-08-02 22:23:50.189272010 +0200
@@ -93,6 +93,10 @@
         os.chdir(orig_path)
 
 
+def get_ext_suffix():
+    return sysconfig.get_config_var("EXT_SUFFIX")
+
+
 def get_python_execute():
     if WINDOWS:
         return sys.executable
@@ -173,6 +177,7 @@
                 f"-DPython3_EXECUTABLE={get_python_execute()}",
                 "-DONNX_BUILD_PYTHON=ON",
                 f"-DONNX_NAMESPACE={ONNX_NAMESPACE}",
+                f"-DPY_EXT_SUFFIX={get_ext_suffix() or ''}",
             ]
             if COVERAGE:
                 cmake_args.append("-DONNX_COVERAGE=ON")