diff --git a/tool/merger.rb b/tool/merger.rb
index 5f48f2eeca4b02..56b7b4a0684a8a 100755
--- a/tool/merger.rb
+++ b/tool/merger.rb
@@ -222,7 +222,7 @@ def commit(file)
 
   def svn_mode?
     return @svn_mode if defined?(@svn_mode)
-    @svn_mode = system("svn info > #{IO::NULL} 2>&1")
+    @svn_mode = system("svn info", %i(out err) => IO::NULL)
   end
 
   # Prints the version of Ruby found in version.h
diff --git a/tool/redmine-backporter.rb b/tool/redmine-backporter.rb
index 1ac001bb6edb53..a7bce96fe29569 100755
--- a/tool/redmine-backporter.rb
+++ b/tool/redmine-backporter.rb
@@ -436,7 +436,7 @@ class << @changesets
       next
     end
 
-    if system("svn info #{RUBY_REPO_PATH&.shellescape} > #{IO::NULL} 2>&1") # SVN
+    if system("svn info #{RUBY_REPO_PATH&.shellescape}", %i(out err) => IO::NULL) # SVN
       if log = find_svn_log("##@issue]") && /revision="(?<rev>\d+)/ =~ log
         rev = "r#{rev}"
       end