diff --git a/media/libnbaio/NBAIO.cpp b/media/libnbaio/NBAIO.cpp
index 290604e..8a8155d 100644
--- a/media/libnbaio/NBAIO.cpp
+++ b/media/libnbaio/NBAIO.cpp
@@ -33,6 +33,8 @@
     return Format_channelCount(format);
 }
 
+const NBAIO_Format Format_Invalid = { 0 };
+
 enum {
     Format_SR_8000,
     Format_SR_11025,