diff --git a/direct/src/interval/SoundInterval.py b/direct/src/interval/SoundInterval.py
index 70524eb0bd..612ae72e19 100644
--- a/direct/src/interval/SoundInterval.py
+++ b/direct/src/interval/SoundInterval.py
@@ -32,7 +32,7 @@ class SoundInterval(Interval.Interval):
         self.startTime = startTime
         # If no duration given use sound's duration as interval's duration
         if duration == 0.0 and self.sound != None:
-            duration = self.sound.length() - self.startTime
+            duration = max(self.sound.length() - self.startTime, 0)
             if (duration == 0):
                 self.notify.warning('zero length duration!')
             # MPG - hack for Miles bug