diff --git a/lib/fluent/plugin/in_tail.rb b/lib/fluent/plugin/in_tail.rb
index 23a2af7c4b..8185df0f5e 100644
--- a/lib/fluent/plugin/in_tail.rb
+++ b/lib/fluent/plugin/in_tail.rb
@@ -147,7 +147,7 @@ def configure(conf)
         raise Fluent::ConfigError, "cannot use glob_policy as always with the default path_delimitor: `,\""
       end
 
-      if @glob_policy == :extended && /\{.*,.*\}/.match(@path) && extended_glob_pattern(@path)
+      if @glob_policy == :extended && /\{.*,.*\}/.match?(@path) && extended_glob_pattern(@path)
         raise Fluent::ConfigError, "cannot include curly braces with glob patterns in `#{@path}\". Use glob_policy always instead."
       end
 
@@ -300,7 +300,7 @@ def have_read_capability?
     end
 
     def extended_glob_pattern(path)
-      path.include?('*') || path.include?('?') || /\[.*\]/.match(path)
+      path.include?('*') || path.include?('?') || /\[.*\]/.match?(path)
     end
 
     # Curly braces is not supported with default path_delimiter
@@ -313,7 +313,7 @@ def use_glob?(path)
         # regular expressions as much as possible.
         # This is because not using `true' as a returning value
         # when choosing :always here.
-        extended_glob_pattern(path) || /\{.*,.*\}/.match(path)
+        extended_glob_pattern(path) || /\{.*,.*\}/.match?(path)
       elsif @glob_policy == :extended
         extended_glob_pattern(path)
       elsif @glob_policy == :backward_compatible
diff --git a/lib/fluent/plugin/out_secondary_file.rb b/lib/fluent/plugin/out_secondary_file.rb
index 5cadf94984..a82fccf78e 100644
--- a/lib/fluent/plugin/out_secondary_file.rb
+++ b/lib/fluent/plugin/out_secondary_file.rb
@@ -98,11 +98,11 @@ def validate_compatible_with_primary_buffer!(path_without_suffix)
         raise Fluent::ConfigError, "out_secondary_file: basename or directory has an incompatible placeholder, remove time formats, like `%Y%m%d`, from basename or directory"
       end
 
-      if !@chunk_key_tag && (ph = placeholders.find { |placeholder| placeholder.match(/tag(\[\d+\])?/) })
+      if !@chunk_key_tag && (ph = placeholders.find { |placeholder| placeholder.match?(/tag(\[\d+\])?/) })
         raise Fluent::ConfigError, "out_secondary_file: basename or directory has an incompatible placeholder #{ph}, remove tag placeholder, like `${tag}`, from basename or directory"
       end
 
-      vars = placeholders.reject { |placeholder| placeholder.match(/tag(\[\d+\])?/) || (placeholder == 'chunk_id') }
+      vars = placeholders.reject { |placeholder| placeholder.match?(/tag(\[\d+\])?/) || (placeholder == 'chunk_id') }
 
       if ph = vars.find { |v| !@chunk_keys.include?(v) }
         raise Fluent::ConfigError, "out_secondary_file: basename or directory has an incompatible placeholder #{ph}, remove variable placeholder, like `${varname}`, from basename or directory"
diff --git a/lib/fluent/plugin/parser.rb b/lib/fluent/plugin/parser.rb
index 0854129f0e..d912521976 100644
--- a/lib/fluent/plugin/parser.rb
+++ b/lib/fluent/plugin/parser.rb
@@ -220,7 +220,7 @@ def convert_values(time, record)
       end
 
       def string_like_null(value, null_empty_string = @null_empty_string, null_value_regexp = @null_value_pattern)
-        null_empty_string && value.empty? || null_value_regexp && string_safe_encoding(value){|s| null_value_regexp.match(s) }
+        null_empty_string && value.empty? || null_value_regexp && string_safe_encoding(value){|s| null_value_regexp.match?(s) }
       end
 
       TRUTHY_VALUES = ['true', 'yes', '1']