diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc85748a..f4fdbe85 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+## 4.2.0
+
+- Added `config.regexp_resolver` configuration option, `'ruby'` (default) or `'ecma'` (also as Symbol). The value is passed to json_schemer's `regexp_resolver` configuration. In OpenAPI, the pattern keyword specifies a regular expression that must conform to the ECMA-262 standard. So using `'ecma'` is recommended.
+
 ## 4.1.0
 
 - Query and cookie parameter values with invalid encoding (like `?search=%C3`) produce a 400 response now. Before such a value passed validation or raised an `ArgumentError`. This applies to documented and undocumented query parameter, but only to documented cookie parameters.
diff --git a/Gemfile.lock b/Gemfile.lock
index cb1213f8..589b22ad 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    openapi_first (4.1.0)
+    openapi_first (4.2.0)
       drb (~> 2.0)
       hana (~> 1.3)
       json_schemer (>= 2.1, < 3.0)
@@ -146,7 +146,7 @@ GEM
       racc (~> 1.4)
     nokogiri (1.19.4-x86_64-linux-gnu)
       racc (~> 1.4)
-    parallel (2.2.0)
+    parallel (2.3.0)
     parser (3.3.12.0)
       ast (~> 2.4.1)
       racc
@@ -246,7 +246,7 @@ GEM
     rubydex (0.4.1-arm64-darwin)
     rubydex (0.4.1-x86_64-linux)
     securerandom (0.4.1)
-    simplecov (1.3.1)
+    simplecov (1.3.2)
     simpleidn (0.3.0)
     sinatra (4.2.1)
       logger (>= 1.6.0)
diff --git a/benchmarks/Gemfile.lock b/benchmarks/Gemfile.lock
index 7ac78ab2..9afb1370 100644
--- a/benchmarks/Gemfile.lock
+++ b/benchmarks/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    openapi_first (4.1.0)
+    openapi_first (4.2.0)
       drb (~> 2.0)
       hana (~> 1.3)
       json_schemer (>= 2.1, < 3.0)
diff --git a/lib/openapi_first/builder.rb b/lib/openapi_first/builder.rb
index ecff7367..0acb7e27 100644
--- a/lib/openapi_first/builder.rb
+++ b/lib/openapi_first/builder.rb
@@ -27,9 +27,9 @@ def self.build_router(contents, filepath:, config:)
     end
 
     def initialize(contents, filepath:, config:)
+      @config = config
       meta_schema = detect_meta_schema(contents, filepath)
       @schemer_configuration = build_schemer_config(filepath:, meta_schema:)
-      @config = config
       @file_loader = FileLoader.new
       ref_resolver = RefResolver.new(file_loader:)
       @contents = ref_resolver.for(contents, filepath:)
@@ -47,6 +47,7 @@ def build_schemer_config(filepath:, meta_schema:)
       end
       result.meta_schema = meta_schema
       result.insert_property_defaults = true
+      result.regexp_resolver = config.regexp_resolver if config.regexp_resolver
       result
     end
 
diff --git a/lib/openapi_first/child_configuration.rb b/lib/openapi_first/child_configuration.rb
index 0a32ebfe..7c842d39 100644
--- a/lib/openapi_first/child_configuration.rb
+++ b/lib/openapi_first/child_configuration.rb
@@ -8,6 +8,7 @@ def initialize(parent:)
       @parent = parent
       @request_validation_error_response = parent.request_validation_error_response
       @path = parent.path
+      @regexp_resolver = parent.regexp_resolver
     end
 
     private attr_reader :parent
diff --git a/lib/openapi_first/configuration.rb b/lib/openapi_first/configuration.rb
index 5479b835..4b33de84 100644
--- a/lib/openapi_first/configuration.rb
+++ b/lib/openapi_first/configuration.rb
@@ -16,13 +16,14 @@ def initialize
       @request_validation_error_response = OpenapiFirst.find_error_response(:default)
       @hooks = HOOKS.to_h { [_1, Set.new] }
       @path = nil
+      @regexp_resolver = nil
     end
 
     def register(path_or_definition, as: :default)
       OpenapiFirst.register(path_or_definition, as:)
     end
 
-    attr_reader :hooks, :request_validation_error_response
+    attr_reader :hooks, :request_validation_error_response, :regexp_resolver
     attr_accessor :path
 
     # Return a child configuration that still receives updates of global hooks.
@@ -49,6 +50,10 @@ def plugin(name, **)
       Plugins.load(name).configure(self, **)
     end
 
+    def regexp_resolver=(resolver)
+      @regexp_resolver = resolver.is_a?(Symbol) ? resolver.to_s : resolver
+    end
+
     def request_validation_error_response=(mod)
       @request_validation_error_response = if mod.is_a?(Symbol)
                                              OpenapiFirst.find_error_response(mod)
diff --git a/lib/openapi_first/version.rb b/lib/openapi_first/version.rb
index f13ceffc..7d5814fd 100644
--- a/lib/openapi_first/version.rb
+++ b/lib/openapi_first/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module OpenapiFirst
-  VERSION = '4.1.0'
+  VERSION = '4.2.0'
 end
diff --git a/spec/configuration_spec.rb b/spec/configuration_spec.rb
index 86695fc7..bc809cbb 100644
--- a/spec/configuration_spec.rb
+++ b/spec/configuration_spec.rb
@@ -39,6 +39,44 @@
     end
   end
 
+  describe '#regexp_resolver=' do
+    let(:document) do
+      {
+        'openapi' => '3.1.0',
+        'info' => { 'title' => 'Ids', 'version' => '1' },
+        'paths' => {
+          '/ids' => {
+            'get' => {
+              'parameters' => [
+                { 'name' => 'ids', 'in' => 'query', 'schema' => { 'type' => 'string', 'pattern' => '^\d+(,\d+)*$' } }
+              ],
+              'responses' => { '200' => { 'description' => 'OK' } }
+            }
+          }
+        }
+      }
+    end
+
+    def valid?(definition, query)
+      request = Rack::Request.new(Rack::MockRequest.env_for("/ids?#{query}"))
+      definition.validate_request(request).valid?
+    end
+
+    it 'anchors ^ and $ to lines by default' do
+      definition = OpenapiFirst.parse(document)
+
+      expect(valid?(definition, 'ids=1,2')).to be(true)
+      expect(valid?(definition, 'ids=1%0Aa')).to be(true)
+    end
+
+    it 'anchors ^ and $ to the whole value with ecma' do
+      definition = OpenapiFirst.parse(document) { |config| config.regexp_resolver = :ecma }
+
+      expect(valid?(definition, 'ids=1,2')).to be(true)
+      expect(valid?(definition, 'ids=1%0Aa')).to be(false)
+    end
+  end
+
   describe '#child' do
     it 'clones actions' do
       config = OpenapiFirst::Configuration.new