diff --git a/Gemfile b/Gemfile
index 8b1b4362..5e9695fb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -36,8 +36,8 @@ gem 'tzinfo-data', platforms: %i[mingw mswin x64_mingw jruby]
 
 group :test do
   gem 'mocha', '~> 3.1.0', require: false
-  gem 'simplecov', '~> 0.22', require: false
-  gem 'simplecov-cobertura', '~> 3.2.0', require: false
+  gem 'simplecov', '~> 1.0', require: false
+  gem 'simplecov-cobertura', '~> 4.0.0', require: false
 end
 
 group :development, :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index aef1971e..2ba52ce9 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -94,7 +94,6 @@ GEM
     debug (1.11.1)
       irb (~> 1.10)
       reline (>= 0.3.8)
-    docile (1.4.1)
     drb (2.2.3)
     erb (6.0.4)
     erubi (1.13.1)
@@ -275,15 +274,10 @@ GEM
       logger
     ruby2_keywords (0.0.5)
     securerandom (0.4.1)
-    simplecov (0.22.0)
-      docile (~> 1.1)
-      simplecov-html (~> 0.11)
-      simplecov_json_formatter (~> 0.1)
-    simplecov-cobertura (3.2.0)
+    simplecov (1.0.1)
+    simplecov-cobertura (4.0.0)
       rexml
-      simplecov (~> 0.19)
-    simplecov-html (0.13.2)
-    simplecov_json_formatter (0.1.4)
+      simplecov (~> 1.0)
     thor (1.5.0)
     timeout (0.6.1)
     tsort (0.2.0)
@@ -328,8 +322,8 @@ DEPENDENCIES
   rubocop-rails (~> 2.35)
   ruby-lsp (~> 0.26.10)
   ruby-vips (~> 2.3.0)
-  simplecov (~> 0.22)
-  simplecov-cobertura (~> 3.2.0)
+  simplecov (~> 1.0)
+  simplecov-cobertura (~> 4.0.0)
   tzinfo-data
   wahwah (~> 1.6.7)
   will_paginate (~> 4.0)
@@ -360,7 +354,6 @@ CHECKSUMS
   crass (1.0.7) sha256=94868719948664c89ddcaf0a37c65048413dfcb1c869470a5f7a7ceb5390b295
   date (3.5.1) sha256=750d06384d7b9c15d562c76291407d89e368dda4d4fff957eb94962d325a0dc0
   debug (1.11.1) sha256=2e0b0ac6119f2207a6f8ac7d4a73ca8eb4e440f64da0a3136c30343146e952b6
-  docile (1.4.1) sha256=96159be799bfa73cdb721b840e9802126e4e03dfc26863db73647204c727f21e
   drb (2.2.3) sha256=0b00d6fdb50995fe4a45dea13663493c841112e4068656854646f418fda13373
   erb (6.0.4) sha256=38e3803694be357fe2bfe312487c74beaf9fb4e5beb3e22498952fe1645b95d9
   erubi (1.13.1) sha256=a082103b0885dbc5ecf1172fede897f9ebdb745a4b97a5e8dc63953db1ee4ad9
@@ -431,10 +424,8 @@ CHECKSUMS
   ruby-vips (2.3.0) sha256=e685ec02c13969912debbd98019e50492e12989282da5f37d05f5471442f5374
   ruby2_keywords (0.0.5) sha256=ffd13740c573b7301cf7a2e61fc857b2a8e3d3aff32545d6f8300d8bae10e3ef
   securerandom (0.4.1) sha256=cc5193d414a4341b6e225f0cb4446aceca8e50d5e1888743fac16987638ea0b1
-  simplecov (0.22.0) sha256=fe2622c7834ff23b98066bb0a854284b2729a569ac659f82621fc22ef36213a5
-  simplecov-cobertura (3.2.0) sha256=70d702658677fcb20e5aceb6915ccf8bc62ff2ccd38b62b3ad5c9db5c0888740
-  simplecov-html (0.13.2) sha256=bd0b8e54e7c2d7685927e8d6286466359b6f16b18cb0df47b508e8d73c777246
-  simplecov_json_formatter (0.1.4) sha256=529418fbe8de1713ac2b2d612aa3daa56d316975d307244399fa4838c601b428
+  simplecov (1.0.1) sha256=419d93c40484159d20b40e26e9a83cdd4c3afa2f3fd443bb8946c301cd658d75
+  simplecov-cobertura (4.0.0) sha256=e4fb3159b1ecea545b44f5452a8611305323e78ad23eae8aed35924d072e01ea
   thor (1.5.0) sha256=e3a9e55fe857e44859ce104a84675ab6e8cd59c650a49106a05f55f136425e73
   timeout (0.6.1) sha256=78f57368a7e7bbadec56971f78a3f5ecbcfb59b7fcbb0a3ed6ddc08a5094accb
   tsort (0.2.0) sha256=9650a793f6859a43b6641671278f79cfead60ac714148aabe4e3f0060480089f
diff --git a/gemset.nix b/gemset.nix
index 6834dde8..112e62ea 100644
--- a/gemset.nix
+++ b/gemset.nix
@@ -315,18 +315,6 @@
     targets = [];
     version = "1.11.1";
   };
-  docile = {
-    groups = ["default" "test"];
-    platforms = [];
-    source = {
-      remotes = ["https://rubygems.org"];
-      sha256 = "07pj4z3h8wk4fgdn6s62vw1lwvhj0ac0x10vfbdkr9xzk7krn5cn";
-      target = "ruby";
-      type = "gem";
-    };
-    targets = [];
-    version = "1.4.1";
-  };
   drb = {
     groups = ["default" "development" "test"];
     platforms = [];
@@ -1209,17 +1197,16 @@
     version = "0.4.1";
   };
   simplecov = {
-    dependencies = ["docile" "simplecov-html" "simplecov_json_formatter"];
     groups = ["test"];
     platforms = [];
     source = {
       remotes = ["https://rubygems.org"];
-      sha256 = "198kcbrjxhhzca19yrdcd6jjj9sb51aaic3b0sc3pwjghg3j49py";
+      sha256 = "0xcdcp6h3hs6i6xl7m1z5zx3lk6x7jlfj9hfnhh9s5c40k2977a1";
       target = "ruby";
       type = "gem";
     };
     targets = [];
-    version = "0.22.0";
+    version = "1.0.1";
   };
   simplecov-cobertura = {
     dependencies = ["rexml" "simplecov"];
@@ -1227,36 +1214,12 @@
     platforms = [];
     source = {
       remotes = ["https://rubygems.org"];
-      sha256 = "0h47i30bb7awmnrn52ykrkr2zilbrxf93dnfb87b5z3phrjh5mvh";
-      target = "ruby";
-      type = "gem";
-    };
-    targets = [];
-    version = "3.2.0";
-  };
-  simplecov-html = {
-    groups = ["default" "test"];
-    platforms = [];
-    source = {
-      remotes = ["https://rubygems.org"];
-      sha256 = "0ikjfwydgs08nm3xzc4cn4b6z6rmcrj2imp84xcnimy2wxa8w2xx";
-      target = "ruby";
-      type = "gem";
-    };
-    targets = [];
-    version = "0.13.2";
-  };
-  simplecov_json_formatter = {
-    groups = ["default" "test"];
-    platforms = [];
-    source = {
-      remotes = ["https://rubygems.org"];
-      sha256 = "0a5l0733hj7sk51j81ykfmlk2vd5vaijlq9d5fn165yyx3xii52j";
+      sha256 = "1sh15q3lv4imxn5awgnjibkj6lrh2632ligm8idm9spcn5ck3yz4";
       target = "ruby";
       type = "gem";
     };
     targets = [];
-    version = "0.1.4";
+    version = "4.0.0";
   };
   thor = {
     groups = ["default" "development" "test"];