diff --git a/Makefile.pre.in b/Makefile.pre.in
index 5b47530a2a7748..4f7284d31356f7 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -1488,6 +1488,7 @@ TESTSUBDIRS=	ctypes/test \
 		test/test_importlib/namespace_pkgs/project3 \
 		test/test_importlib/namespace_pkgs/project3/parent \
 		test/test_importlib/namespace_pkgs/project3/parent/child \
+		test/test_importlib/namespacedata01 \
 		test/test_importlib/partial \
 		test/test_importlib/source \
 		test/test_importlib/zipdata01 \