diff --git a/plugins/pyloader/m4/ac_python_devel.m4 b/plugins/pyloader/m4/ac_python_devel.m4
index 682aad5..77b2fd0 100644
--- a/plugins/pyloader/m4/ac_python_devel.m4
+++ b/plugins/pyloader/m4/ac_python_devel.m4
@@ -254,6 +254,8 @@ EOD`
 	#
 	AC_MSG_CHECKING([consistency of all components of python development environment])
 	# save current global flags
+	ac_save_LIBS="$LIBS"
+	ac_save_CPPFLAGS="$CPPFLAGS"
 	LIBS="$ac_save_LIBS $PYTHON_LDFLAGS $PYTHON_EXTRA_LDFLAGS $PYTHON_EXTRA_LIBS"
 	CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
 	AC_LANG_PUSH([C])