Index: src/OFTimer.m
==================================================================
--- src/OFTimer.m
+++ src/OFTimer.m
@@ -368,11 +368,11 @@
 
 	[condition lock];
 	[condition signal];
 	[condition unlock];
 
-	if (repeats) {
+	if (repeats && isValid) {
 		OFDate *old = fireDate;
 		fireDate = [[OFDate alloc]
 		    initWithTimeIntervalSinceNow: interval];
 		[old release];