diff --git a/include/bx/readerwriter.h b/include/bx/readerwriter.h
index 7fda6f0..0866c88 100644
--- a/include/bx/readerwriter.h
+++ b/include/bx/readerwriter.h
@@ -8,6 +8,7 @@
 
 #include "allocator.h"
 #include "error.h"
+#include "endian.h"
 #include "uint32_t.h"
 
 BX_ERROR_RESULT(BX_ERROR_READERWRITER_OPEN,         BX_MAKEFOURCC('R', 'W', 0, 1) );