diff --git a/Misc/NEWS b/Misc/NEWS
index c6a4d3f..260ee3f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -679,6 +679,8 @@
 Tools/Demos
 -----------
 
+- Issue #25440: Fix output of python-config --extension-suffix.
+
 - Issue #23330: h2py now supports arbitrary filenames in #include.
 
 - Issue #24031: make patchcheck now supports git checkouts, too.
diff --git a/Misc/python-config.sh.in b/Misc/python-config.sh.in
index 64c81e5..30c6927 100644
--- a/Misc/python-config.sh.in
+++ b/Misc/python-config.sh.in
@@ -49,7 +49,7 @@
 LDVERSION="@LDVERSION@"
 LIBDEST=${prefix}/lib/python${VERSION}
 LIBPL=$(echo "@LIBPL@" | sed "s#$prefix_build#$prefix_real#")
-SO="@SO@"
+SO="@EXT_SUFFIX@"
 PYTHONFRAMEWORK="@PYTHONFRAMEWORK@"
 INCDIR="-I$includedir/python${VERSION}${ABIFLAGS}"
 PLATINCDIR="-I$includedir/python${VERSION}${ABIFLAGS}"