diff --git a/media/extractors/mp4/MPEG4Extractor.cpp b/media/extractors/mp4/MPEG4Extractor.cpp
index 1a56edc..7b3b81d 100644
--- a/media/extractors/mp4/MPEG4Extractor.cpp
+++ b/media/extractors/mp4/MPEG4Extractor.cpp
@@ -1023,7 +1023,9 @@
                     break;
                 }
             }
-            mLastTrack->meta.setInt32(kKeyCryptoMode, mode);
+            if (mode != kCryptoModeUnencrypted) {
+                mLastTrack->meta.setInt32(kKeyCryptoMode, mode);
+            }
             break;
         }