diff --git a/libavcodec/amrwbdata.h b/libavcodec/amrwbdata.h
index 47b0d42a9c..36553d5a0f 100644
--- a/libavcodec/amrwbdata.h
+++ b/libavcodec/amrwbdata.h
@@ -28,6 +28,7 @@
 #define AVCODEC_AMRWBDATA_H
 
 #include <stdint.h>
+#include <stddef.h>
 
 #define LP_ORDER            16                ///< linear predictive coding filter order
 #define LP_ORDER_16k        20                ///< lpc filter order at 16kHz