diff --git a/desmume/src/types.h b/desmume/src/types.h
index b74032eb8..1028e7fe2 100644
--- a/desmume/src/types.h
+++ b/desmume/src/types.h
@@ -197,7 +197,9 @@ typedef int desmume_BOOL;
 #endif
 
 #ifdef __BIG_ENDIAN__
+#ifndef WORDS_BIGENDIAN
 #define WORDS_BIGENDIAN
+#endif
 #endif
 
 #ifdef WORDS_BIGENDIAN