1 files changed, 1 insertions, 1 deletions
diff --git a/string.c b/string.c
index b5fc5f3446..62c494ac73 100644
--- a/string.c
+++ b/string.c
@@ -2650,7 +2650,7 @@ rb_str_dump(str)
 	  case '"':  case '\\':
 	  case '\n': case '\r':
 	  case '\t': case '\f':
-	  case '\013': case '\007': case '\033':
+	  case '\013': case '\010': case '\007': case '\033':
 	    len += 2;
 	    break;