diff --git a/Gemfile.lock b/Gemfile.lock
index ff2cff6..5059e2d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -66,7 +66,8 @@ GEM
     regexp_parser (2.5.0)
     reverse_markdown (2.1.1)
       nokogiri
-    rexml (3.2.5)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rouge (3.29.0)
     rspec (3.11.0)
       rspec-core (~> 3.11.0)
@@ -110,6 +111,7 @@ GEM
       unicode-display_width (>= 1.5, < 3.0)
       unicode_utils (~> 1.4)
     strings-ansi (0.2.0)
+    strscan (3.1.0)
     thor (1.2.1)
     tty-color (0.6.0)
     tty-cursor (0.7.1)