diff --git a/spec/rubocop/cli/auto_gen_config_spec.rb b/spec/rubocop/cli/auto_gen_config_spec.rb
index 0691669b41e..dbe24fd500f 100644
--- a/spec/rubocop/cli/auto_gen_config_spec.rb
+++ b/spec/rubocop/cli/auto_gen_config_spec.rb
@@ -824,7 +824,7 @@ def a; end
               - 'example1.rb'
               - 'example2.rb'
         YAML
-        actual = File.read('.rubocop_todo.yml').lines.reject { |line| line =~ /^(#.*)?$/ }
+        actual = File.read('.rubocop_todo.yml').lines.grep_v(/^(#.*)?$/)
         expect(actual.join).to eq(expected)
 
         $stdout = StringIO.new
@@ -842,7 +842,7 @@ def a; end
               Exclude:
                 - 'example2.rb'
           YAML
-          actual = File.read('.rubocop_todo.yml').lines.reject { |line| line =~ /^(#.*)?$/ }
+          actual = File.read('.rubocop_todo.yml').lines.grep_v(/^(#.*)?$/)
           expect(actual.join).to eq(expected)
 
           expect(cli.run([])).to eq(0)
diff --git a/spec/support/alignment_examples.rb b/spec/support/alignment_examples.rb
index 64795f846e9..0366fed86f9 100644
--- a/spec/support/alignment_examples.rb
+++ b/spec/support/alignment_examples.rb
@@ -10,7 +10,7 @@
                              end
   annotated_source.split("\n\n").each do |chunk|
     chunk << "\n" unless chunk.end_with?("\n")
-    source = chunk.lines.reject { |line| /^ *\^/.match?(line) }.join
+    source = chunk.lines.grep_v(/^ *\^/).join
     name = source.gsub(/\n(?=[a-z ])/, ' <newline> ').gsub(/\s+/, ' ')
 
     it "registers an offense for mismatched #{name} and autocorrects" do