diff --git a/ext/psych/lib/psych/visitors/to_ruby.rb b/ext/psych/lib/psych/visitors/to_ruby.rb
index f0fda9bdbc..9e4da5ef0d 100644
--- a/ext/psych/lib/psych/visitors/to_ruby.rb
+++ b/ext/psych/lib/psych/visitors/to_ruby.rb
@@ -36,7 +36,7 @@ module Psych
 
         unless @domain_types.empty? || !target.tag
           key = target.tag.sub(/^[!\/]*/, '').sub(/(,\d+)\//, '\1:')
-          key = "tag:#{key}" unless key =~ /^(?:tag:|x-private)/
+          key = "tag:#{key}" unless key.match?(/^(?:tag:|x-private)/)
 
           if @domain_types.key? key
             value, block = @domain_types[key]
diff --git a/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index a2ebc4d781..e27c927996 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/lib/psych/visitors/yaml_tree.rb
@@ -261,7 +261,7 @@ module Psych
           style = Nodes::Scalar::LITERAL
           plain = false
           quote = false
-        elsif o =~ /\n(?!\Z)/  # match \n except blank line at the end of string
+        elsif o.match?(/\n(?!\Z)/)  # match \n except blank line at the end of string
           style = Nodes::Scalar::LITERAL
         elsif o == '<<'
           style = Nodes::Scalar::SINGLE_QUOTED
@@ -272,9 +272,9 @@ module Psych
           style = Nodes::Scalar::DOUBLE_QUOTED
         elsif @line_width && o.length > @line_width
           style = Nodes::Scalar::FOLDED
-        elsif o =~ /^[^[:word:]][^"]*$/
+        elsif o.match?(/^[^[:word:]][^"]*$/)
           style = Nodes::Scalar::DOUBLE_QUOTED
-        elsif not String === @ss.tokenize(o) or /\A0[0-7]*[89]/ =~ o
+        elsif not String === @ss.tokenize(o) or /\A0[0-7]*[89]/.match?(o)
           style = Nodes::Scalar::SINGLE_QUOTED
         end