diff --git a/Gemfile.lock b/Gemfile.lock
index 8d2aa78..a555a79 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -134,6 +134,8 @@ GEM
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
+    psych (5.1.2)
+      stringio
     puma (5.6.8)
       nio4r (~> 2.0)
     racc (1.7.3)
@@ -175,7 +177,8 @@ GEM
       thor (~> 1.0, >= 1.2.2)
       zeitwerk (~> 2.6)
     rake (13.1.0)
-    rdoc (2.5.11)
+    rdoc (6.6.2)
+      psych (>= 4.0.0)
     reline (0.4.2)
       io-console (~> 0.5)
     resend (0.10.0)
@@ -183,6 +186,7 @@ GEM
     ruby2_keywords (0.0.5)
     sqlite3 (1.6.2-x86_64-darwin)
     sqlite3 (1.6.2-x86_64-linux)
+    stringio (3.1.0)
     thor (1.3.0)
     timeout (0.4.1)
     tzinfo (2.0.6)