diff -urN expect5.45/exp_clib.c expect5.45-patched/exp_clib.c
--- expect5.45/exp_clib.c	2010-09-01 09:20:27.000000000 +1100
+++ expect5.45-patched/exp_clib.c	2012-06-08 01:21:05.181612888 +1100
@@ -1476,8 +1476,8 @@
      char *str;
 {
   if (exp_is_debugging) {
-    fprintf(stderr,str);
-    if (exp_logfile) fprintf(exp_logfile,str);
+    fprintf(stderr,"%s",str);
+    if (exp_logfile) fprintf(exp_logfile,"%s",str);
   }
 }