diff --git a/lib/multi.c b/lib/multi.c
index a79f2ef1f8..49be772a31 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -3422,20 +3422,10 @@ static CURLMcode multi_timeout(struct Curl_multi *multi,
 
     if(Curl_splaycomparekeys(multi->timetree->key, now) > 0) {
       /* some time left before expiration */
-      timediff_t diff = Curl_timediff(multi->timetree->key, now);
-      if(diff <= 0)
-        /*
-         * Since we only provide millisecond resolution on the returned value
-         * and the diff might be less than one millisecond here, we don't
-         * return zero as that may cause short bursts of busyloops on fast
-         * processors while the diff is still present but less than one
-         * millisecond! instead we return 1 until the time is ripe.
-         */
-        *timeout_ms = 1;
-      else
-        /* this should be safe even on 64 bit archs, as we don't use that
-           overly long timeouts */
-        *timeout_ms = (long)diff;
+      timediff_t diff = Curl_timediff_ceil(multi->timetree->key, now);
+      /* this should be safe even on 32 bit archs, as we don't use that
+         overly long timeouts */
+      *timeout_ms = (long)diff;
     }
     else
       /* 0 means immediately */
diff --git a/lib/timeval.c b/lib/timeval.c
index 2de79be46d..026d9d17cd 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -209,6 +209,20 @@ timediff_t Curl_timediff(struct curltime newer, struct curltime older)
   return diff * 1000 + (newer.tv_usec-older.tv_usec)/1000;
 }
 
+/*
+ * Returns: time difference in number of milliseconds, rounded up.
+ * For too large diffs it returns max value.
+ */
+timediff_t Curl_timediff_ceil(struct curltime newer, struct curltime older)
+{
+  timediff_t diff = (timediff_t)newer.tv_sec-older.tv_sec;
+  if(diff >= (TIMEDIFF_T_MAX/1000))
+    return TIMEDIFF_T_MAX;
+  else if(diff <= (TIMEDIFF_T_MIN/1000))
+    return TIMEDIFF_T_MIN;
+  return diff * 1000 + (newer.tv_usec - older.tv_usec + 999)/1000;
+}
+
 /*
  * Returns: time difference in number of microseconds. For too large diffs it
  * returns max value.
diff --git a/lib/timeval.h b/lib/timeval.h
index 92e484ad1d..33dfb5b10d 100644
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -36,16 +36,24 @@ struct curltime {
 struct curltime Curl_now(void);
 
 /*
- * Make sure that the first argument (t1) is the more recent time and t2 is
- * the older time, as otherwise you get a weird negative time-diff back...
+ * Make sure that the first argument (newer) is the more recent time and older
+ * is the older time, as otherwise you get a weird negative time-diff back...
  *
  * Returns: the time difference in number of milliseconds.
  */
-timediff_t Curl_timediff(struct curltime t1, struct curltime t2);
+timediff_t Curl_timediff(struct curltime newer, struct curltime older);
 
 /*
- * Make sure that the first argument (t1) is the more recent time and t2 is
- * the older time, as otherwise you get a weird negative time-diff back...
+ * Make sure that the first argument (newer) is the more recent time and older
+ * is the older time, as otherwise you get a weird negative time-diff back...
+ *
+ * Returns: the time difference in number of milliseconds, rounded up.
+ */
+timediff_t Curl_timediff_ceil(struct curltime newer, struct curltime older);
+
+/*
+ * Make sure that the first argument (newer) is the more recent time and older
+ * is the older time, as otherwise you get a weird negative time-diff back...
  *
  * Returns: the time difference in number of microseconds.
  */