diff --git a/src/ae.c b/src/ae.c
index bee9d4ad..e66808a8 100644
--- a/src/ae.c
+++ b/src/ae.c
@@ -368,19 +368,22 @@ int aeProcessEvents(aeEventLoop *eventLoop, int flags)
         if (shortest) {
             long now_sec, now_ms;
 
-            /* Calculate the time missing for the nearest
-             * timer to fire. */
             aeGetTime(&now_sec, &now_ms);
             tvp = &tv;
-            tvp->tv_sec = shortest->when_sec - now_sec;
-            if (shortest->when_ms < now_ms) {
-                tvp->tv_usec = ((shortest->when_ms+1000) - now_ms)*1000;
-                tvp->tv_sec --;
+
+            /* How many milliseconds we need to wait for the next
+             * time event to fire? */
+            long long ms =
+                (shortest->when_sec - now_sec)*1000 +
+                shortest->when_ms - now_ms;
+
+            if (ms > 0) {
+                tvp->tv_sec = ms/1000;
+                tvp->tv_usec = (ms % 1000)*1000;
             } else {
-                tvp->tv_usec = (shortest->when_ms - now_ms)*1000;
+                tvp->tv_sec = 0;
+                tvp->tv_usec = 0;
             }
-            if (tvp->tv_sec < 0) tvp->tv_sec = 0;
-            if (tvp->tv_usec < 0) tvp->tv_usec = 0;
         } else {
             /* If we have to check for events but need to return
              * ASAP because of AE_DONT_WAIT we need to set the timeout