diff --git a/Gemfile.lock b/Gemfile.lock
index 874c671..894d553 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -22,7 +22,8 @@ GEM
     rainbow (3.1.1)
     rake (12.3.3)
     regexp_parser (2.8.0)
-    rexml (3.2.5)
+    rexml (3.3.3)
+      strscan
     rspec (3.12.0)
       rspec-core (~> 3.12.0)
       rspec-expectations (~> 3.12.0)
@@ -63,6 +64,7 @@ GEM
     standard-performance (1.0.1)
       lint_roller (~> 1.0)
       rubocop-performance (~> 1.16.0)
+    strscan (3.1.0)
     unicode-display_width (2.4.2)
 
 PLATFORMS