diff --git a/media/libstagefright/SampleTable.cpp b/media/libstagefright/SampleTable.cpp
index ef4d3d06d9f67..eb135abd0a245 100644
--- a/media/libstagefright/SampleTable.cpp
+++ b/media/libstagefright/SampleTable.cpp
@@ -220,7 +220,7 @@ status_t SampleTable::setSampleSizeParams(
             return ERROR_MALFORMED;
         }
 
-        mSampleSizeFieldSize = mDefaultSampleSize & 0xf;
+        mSampleSizeFieldSize = mDefaultSampleSize & 0xff;
         mDefaultSampleSize = 0;
 
         if (mSampleSizeFieldSize != 4 && mSampleSizeFieldSize != 8