2 files changed, 5 insertions, 1 deletions
diff --git a/tools/mirb/mirb.c b/tools/mirb/mirb.c
index 008829cfb..cde0b0d4b 100644
--- a/tools/mirb/mirb.c
+++ b/tools/mirb/mirb.c
@@ -273,7 +273,7 @@ main(int argc, char **argv)
       printf("\n");
       break;
     }
-    strncat(last_code_line, line, sizeof(last_code_line)-1);
+    strncpy(last_code_line, line, sizeof(last_code_line)-1);
     add_history(line);
     free(line);
 #endif
diff --git a/tools/mrbc/mrbc.c b/tools/mrbc/mrbc.c
index 9eb7e9614..cb4de6d2a 100644
--- a/tools/mrbc/mrbc.c
+++ b/tools/mrbc/mrbc.c
@@ -215,6 +215,10 @@ main(int argc, char **argv)
   }
   if (args.initname) {
     n = mrb_dump_irep_cfunc(mrb, n, args.debug_info, args.wfp, args.initname);
+    if (n == MRB_DUMP_INVALID_ARGUMENT) {
+      printf("%s: Invalid C language symbol name\n", args.initname);
+      return EXIT_FAILURE;
+    }
   }
   else {
     n = mrb_dump_irep_binary(mrb, n, args.debug_info, args.wfp);