diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index 128ce8b..258bed8 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -613,7 +613,7 @@
 
     CHECK(source.get() != NULL);
 
-    const char *mime;
+    const char *mime = NULL;
     sp<MetaData> meta = source->getFormat();
     meta->findCString(kKeyMIMEType, &mime);