diff --git a/Gemfile.lock b/Gemfile.lock
index 01c417b..307cd5e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -17,7 +17,8 @@ GEM
       ast (~> 2.4.1)
     rainbow (3.0.0)
     regexp_parser (2.2.0)
-    rexml (3.2.5)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rspec (3.6.0)
       rspec-core (~> 3.6.0)
       rspec-expectations (~> 3.6.0)
@@ -49,6 +50,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
+    strscan (3.1.0)
     unicode-display_width (2.1.0)
 
 PLATFORMS