diff --git a/tests/server/util.c b/tests/server/util.c
index b8a47b1fbb..c36f8eade3 100644
--- a/tests/server/util.c
+++ b/tests/server/util.c
@@ -54,6 +54,7 @@
 #include "getpart.h"
 #include "util.h"
 #include "timeval.h"
+#include "timediff.h"
 
 #ifdef USE_WINSOCK
 #undef  EINTR
@@ -221,6 +222,19 @@ FILE *test2fopen(long testno, const char *logdir2)
   return stream;
 }
 
+#if !defined(MSDOS) && !defined(USE_WINSOCK)
+static long timediff(struct timeval newer, struct timeval older)
+{
+  timediff_t diff = newer.tv_sec-older.tv_sec;
+  if(diff >= (LONG_MAX/1000))
+    return LONG_MAX;
+  else if(diff <= (LONG_MIN/1000))
+    return LONG_MIN;
+  return (long)(newer.tv_sec-older.tv_sec)*1000+
+    (long)(newer.tv_usec-older.tv_usec)/1000;
+}
+#endif
+
 /*
  * Portable function used for waiting a specific amount of ms.
  * Waiting indefinitely with this function is not allowed, a
@@ -457,17 +471,6 @@ static struct timeval tvnow(void)
 
 #endif
 
-long timediff(struct timeval newer, struct timeval older)
-{
-  timediff_t diff = newer.tv_sec-older.tv_sec;
-  if(diff >= (LONG_MAX/1000))
-    return LONG_MAX;
-  else if(diff <= (LONG_MIN/1000))
-    return LONG_MIN;
-  return (long)(newer.tv_sec-older.tv_sec)*1000+
-    (long)(newer.tv_usec-older.tv_usec)/1000;
-}
-
 /* vars used to keep around previous signal handlers */
 
 typedef void (*SIGHANDLER_T)(int);
diff --git a/tests/server/util.h b/tests/server/util.h
index 69121c587f..105e4f73c1 100644
--- a/tests/server/util.h
+++ b/tests/server/util.h
@@ -37,7 +37,6 @@ enum {
 
 char *data_to_hex(char *data, size_t len);
 void logmsg(const char *msg, ...) CURL_PRINTF(1, 2);
-long timediff(struct timeval newer, struct timeval older);
 
 #define SERVERLOGS_LOCKDIR "lock"  /* within logdir */