1 files changed, 3 insertions, 2 deletions
diff --git a/MinuteSecondFormatter.m b/MinuteSecondFormatter.m
index 96f930f..bd33206 100644
--- a/MinuteSecondFormatter.m
+++ b/MinuteSecondFormatter.m
@@ -17,8 +17,9 @@
         return @"--:--";
 
     SInt32 ms = [milliseconds intValue];
-    return [NSString stringWithFormat:@"%i:%02u",
-            ms / 60 / 1000, abs(ms) / 1000 % 60];
+    return [NSString stringWithFormat:@"%s%i:%02u",
+            0 > ms ? "-" : "",
+            abs(ms) / 60 / 1000, abs(ms) / 1000 % 60];
 }
 
 -(BOOL)getObjectValue:(id *)value forString:(NSString *)string