--- ddd-3.3.12-orig/ddd/strclass.C
+++ ddd-3.3.12/ddd/strclass.C
@@ -39,6 +39,7 @@
 #include <limits.h>
 #include <new>
 #include <stdlib.h>
+#include <stdio.h>
 
 void string::error(const char* msg) const
 {