diff --git a/panda/src/audiotraits/openalAudioSound.I b/panda/src/audiotraits/openalAudioSound.I
index 8a60ece6e5..9a090adc3d 100644
--- a/panda/src/audiotraits/openalAudioSound.I
+++ b/panda/src/audiotraits/openalAudioSound.I
@@ -98,5 +98,5 @@ is_playing() const {
  */
 INLINE bool OpenALAudioSound::
 has_sound_data() const {
-  return _sd != 0;
+  return _sd != NULL;
 }