diff --git a/lang/m2/m2mm/options.c b/lang/m2/m2mm/options.c
index 6c0b95664..0cb8c432b 100644
--- a/lang/m2/m2mm/options.c
+++ b/lang/m2/m2mm/options.c
@@ -85,10 +85,10 @@ AddInclDir(text)
 					(unsigned)(mDEF * sizeof(char *)));
 	}
 
-	for (i = ndirs++; i <= nDEF; i++) {
+	for (i = ndirs++; i < nDEF; i++) {
 		char *tmp = DEFPATH[i];
 
-		DEFPATH[i++] = new;
+		DEFPATH[i] = new;
 		new = tmp;
 	}
 }