diff --git a/Gemfile.lock b/Gemfile.lock
index e9d82270a0..d575ac05d5 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -19,7 +19,7 @@ GEM
     parallel (1.22.1)
     parser (3.1.2.1)
       ast (~> 2.4.1)
-    power_assert (2.0.1)
+    power_assert (2.0.2)
     pry (0.14.1)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -47,7 +47,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    test-unit (3.5.3)
+    test-unit (3.5.7)
       power_assert
     timecop (0.9.5)
     unicode-display_width (2.2.0)
@@ -66,7 +66,7 @@ DEPENDENCIES
   rubocop (= 1.36.0)
   rubocop-rake (= 0.6.0)
   simplecov (= 0.17.1, < 0.18)
-  test-unit (= 3.5.3)
+  test-unit (= 3.5.7)
   timecop (= 0.9.5)
   yard (= 0.9.27)
 
diff --git a/faker.gemspec b/faker.gemspec
index 0087b9d574..20fbd00d23 100644
--- a/faker.gemspec
+++ b/faker.gemspec
@@ -40,7 +40,7 @@ Gem::Specification.new do |spec|
   # Stop upgrading SimpleCov until the following issue will be resolved.
   # https://github.com/codeclimate/test-reporter/issues/418
   spec.add_development_dependency('simplecov', '0.17.1', '< 0.18')
-  spec.add_development_dependency('test-unit', '3.5.3')
+  spec.add_development_dependency('test-unit', '3.5.7')
   spec.add_development_dependency('timecop', '0.9.5')
   spec.add_development_dependency('yard', '0.9.27')
 end