diff --git a/dlls/kernel32/tests/actctx.c b/dlls/kernel32/tests/actctx.c
index 8a8d03e..8e86a99 100644
--- a/dlls/kernel32/tests/actctx.c
+++ b/dlls/kernel32/tests/actctx.c
@@ -195,6 +195,7 @@ static BOOL create_manifest_file(const char *filename, const char *manifest, int
     DWORD size;
     HANDLE file;
     WCHAR path[MAX_PATH];
+    FILETIME now;
 
     MultiByteToWideChar( CP_ACP, 0, filename, -1, path, MAX_PATH );
     GetFullPathNameW(path, sizeof(manifest_path)/sizeof(WCHAR), manifest_path, NULL);
@@ -208,6 +209,10 @@ static BOOL create_manifest_file(const char *filename, const char *manifest, int
     if(file == INVALID_HANDLE_VALUE)
         return FALSE;
     WriteFile(file, manifest, manifest_len, &size, NULL);
+    /* Vista+ seems to cache presence of .manifest files. Change last modified
+       date to defeat the cache */
+    GetSystemTimeAsFileTime(&now);
+    SetFileTime(file, NULL, NULL, &now);
     CloseHandle(file);
 
     if (depmanifest)