diff --git a/libavcodec/vp8.h b/libavcodec/vp8.h
index eb4aad278f..219348785a 100644
--- a/libavcodec/vp8.h
+++ b/libavcodec/vp8.h
@@ -34,6 +34,8 @@
 #include <pthread.h>
 #elif HAVE_W32THREADS
 #include "w32pthreads.h"
+#elif HAVE_OS2THREADS
+#include "os2threads.h"
 #endif
 
 #define VP8_MAX_QUANT 127