diff --git a/dlls/scrrun/tests/filesystem.c b/dlls/scrrun/tests/filesystem.c
index b86c43c3ba8..c48baa4f099 100644
--- a/dlls/scrrun/tests/filesystem.c
+++ b/dlls/scrrun/tests/filesystem.c
@@ -29,7 +29,7 @@
 #include "initguid.h"
 #include "scrrun.h"
 
-void test_interfaces(void)
+static void test_interfaces(void)
 {
     HRESULT hr;
     IDispatch *disp;