diff --git a/Gemfile b/Gemfile
index 4b07019..5d20366 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,7 +21,7 @@ group :test do
   gem 'rack-test'
   gem 'rubocop-performance'
   gem 'rubocop-sequel'
-  gem 'simplecov'
+  gem 'simplecov', '0.17.1'
   gem 'vcr'
   gem 'webmock'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index bde101d..21bbdc0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -17,6 +17,7 @@ GEM
     i18n (1.8.2)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.4)
+    json (2.3.0)
     kgio (2.11.3)
     minitest (5.14.0)
     minitest-around (0.5.0)
@@ -67,10 +68,11 @@ GEM
     sequel_pg (1.12.5)
       pg (>= 0.18.0, != 1.2.0)
       sequel (>= 4.38.0)
-    simplecov (0.18.5)
+    simplecov (0.17.1)
       docile (~> 1.1)
-      simplecov-html (~> 0.11)
-    simplecov-html (0.12.2)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.2)
     sinatra (2.0.8.1)
       mustermann (~> 1.0)
       rack (~> 2.0)
@@ -106,7 +108,7 @@ DEPENDENCIES
   rubocop-sequel
   rufus-scheduler
   sequel_pg
-  simplecov
+  simplecov (= 0.17.1)
   sinatra
   unicorn
   vcr