diff --git a/media/libstagefright/avc_utils.cpp b/media/libstagefright/avc_utils.cpp
index 020e947a9d225..8a42e8b4b0484 100644
--- a/media/libstagefright/avc_utils.cpp
+++ b/media/libstagefright/avc_utils.cpp
@@ -188,7 +188,7 @@ status_t getNextNALUnit(
     }
 
     size_t endOffset = offset - 2;
-    while (data[endOffset - 1] == 0x00) {
+    while (endOffset > startOffset + 1 && data[endOffset - 1] == 0x00) {
         --endOffset;
     }