diff --git a/tests/server/sws.c b/tests/server/sws.c
index b79b40c3e..dabcffa41 100644
--- a/tests/server/sws.c
+++ b/tests/server/sws.c
@@ -226,7 +226,7 @@ static void win32_perror (const char *msg)
 }
 #endif
 
-static char *test2file(int testno)
+static char *test2file(long testno)
 {
   static char filename[256];
   sprintf(filename, TEST_DATA_PATH, path, testno);