diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 8ae5f7ffc..574a8daab 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -231,13 +231,6 @@ Lint/ParenthesesAsGroupedExpression:
     - 'test/unit/attachment_test.rb'
     - 'test/unit/lib/redmine/export/pdf_test.rb'
 
-# This cop supports safe autocorrection (--autocorrect).
-Lint/RedundantStringCoercion:
-  Exclude:
-    - 'lib/redmine/export/pdf/issues_pdf_helper.rb'
-    - 'test/functional/repositories_filesystem_controller_test.rb'
-    - 'test/functional/repositories_git_controller_test.rb'
-
 # This cop supports safe autocorrection (--autocorrect).
 Lint/SendWithMixinArgument:
   Exclude:
diff --git a/lib/redmine/export/pdf/issues_pdf_helper.rb b/lib/redmine/export/pdf/issues_pdf_helper.rb
index 1b94685f3..b74531b38 100644
--- a/lib/redmine/export/pdf/issues_pdf_helper.rb
+++ b/lib/redmine/export/pdf/issues_pdf_helper.rb
@@ -38,7 +38,7 @@ module Redmine
           i = 1
           issue.ancestors.visible.each do |ancestor|
             pdf.set_x(base_x + i)
-            buf = "#{ancestor.tracker} # #{ancestor.id} (#{ancestor.status.to_s}): #{ancestor.subject}"
+            buf = "#{ancestor.tracker} # #{ancestor.id} (#{ancestor.status}): #{ancestor.subject}"
             pdf.RDMMultiCell(190 - i, 5, buf)
             i += 1 if i < 35
           end
diff --git a/test/functional/repositories_filesystem_controller_test.rb b/test/functional/repositories_filesystem_controller_test.rb
index 54d3eea7c..0bcb690f3 100644
--- a/test/functional/repositories_filesystem_controller_test.rb
+++ b/test/functional/repositories_filesystem_controller_test.rb
@@ -126,7 +126,7 @@ class RepositoriesFilesystemControllerTest < Redmine::RepositoryControllerTest
         if @ruby19_non_utf8_pass
           puts "TODO: show repository file contents test fails " \
                "when Encoding.default_external is not UTF-8. " \
-               "Current value is '#{Encoding.default_external.to_s}'"
+               "Current value is '#{Encoding.default_external}'"
         else
           assert_select 'tr#L3 td.line-code', :text => /日本語/
         end
diff --git a/test/functional/repositories_git_controller_test.rb b/test/functional/repositories_git_controller_test.rb
index 70d795068..7ac853594 100644
--- a/test/functional/repositories_git_controller_test.rb
+++ b/test/functional/repositories_git_controller_test.rb
@@ -832,6 +832,6 @@ class RepositoriesGitControllerTest < Redmine::RepositoryControllerTest
   def puts_pass_on_not_utf8
     puts "TODO: This test fails " +
          "when Encoding.default_external is not UTF-8. " +
-         "Current value is '#{Encoding.default_external.to_s}'"
+         "Current value is '#{Encoding.default_external}'"
   end
 end