diff --git a/Gemfile.lock b/Gemfile.lock
index efaba83..5cae510 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -23,7 +23,8 @@ GEM
     rainbow (3.0.0)
     rake (12.3.3)
     regexp_parser (2.1.1)
-    rexml (3.2.5)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rubocop (1.5.2)
       parallel (~> 1.10)
       parser (>= 2.7.1.5)
@@ -42,6 +43,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.3)
+    strscan (3.1.0)
     unicode-display_width (1.7.0)
     yard (0.9.34)