diff --git a/Gemfile.lock b/Gemfile.lock
index 2864c0e..f4c8e82 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -14,7 +14,6 @@ GEM
       bigdecimal
       rexml
     diff-lcs (1.6.2)
-    docile (1.4.1)
     drb (2.2.3)
     hana (1.3.7)
     hashdiff (1.2.1)
@@ -75,12 +74,7 @@ GEM
       rubocop-ast (>= 1.47.1, < 2.0)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
-    simplecov (0.22.0)
-      docile (~> 1.1)
-      simplecov-html (~> 0.11)
-      simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.13.2)
-    simplecov_json_formatter (0.1.4)
+    simplecov (1.0.0)
     simpleidn (0.2.3)
     standard (1.54.0)
       language_server-protocol (~> 3.17.0.2)
@@ -115,7 +109,7 @@ DEPENDENCIES
   mocha (~> 3.0)
   rake (~> 13.4)
   rspec (~> 3.0)
-  simplecov (~> 0.22.0)
+  simplecov (~> 1.0.0)
   standardrb
   webmock (~> 3.0)
 
diff --git a/lizard.gemspec b/lizard.gemspec
index d1a79a9..b458766 100644
--- a/lizard.gemspec
+++ b/lizard.gemspec
@@ -28,7 +28,7 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "minitest", ">= 5.0"
   spec.add_development_dependency "rspec", "~> 3.0"
-  spec.add_development_dependency "simplecov", "~> 0.22.0"
+  spec.add_development_dependency "simplecov", "~> 1.0.0"
   spec.add_development_dependency "webmock", "~> 3.0"
   spec.add_development_dependency "json_schemer", "~> 2.0"
   spec.add_development_dependency "mocha", "~> 3.0"