diff --git a/mex/sources/mjdgges/mjdgges.c b/mex/sources/mjdgges/mjdgges.c
index 92929d348..77c4337cf 100644
--- a/mex/sources/mjdgges/mjdgges.c
+++ b/mex/sources/mjdgges/mjdgges.c
@@ -20,7 +20,7 @@
 #include <string.h>
 #include "mex.h"
 
-#ifdef MWTYPES_NOT_DEFINED
+#if defined(MWTYPES_NOT_DEFINED) || defined(OCTAVE)
 typedef int mwSignedIndex;
 #endif