diff --git a/modules/openapi-generator/src/main/resources/dart2/api_client.mustache b/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
index 8eae959e3e5..d8db09013b9 100644
--- a/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
+++ b/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
@@ -183,6 +183,8 @@ class ApiClient {
           }
           final valueString = '$value'.toLowerCase();
           return valueString == 'true' || valueString == '1';
+        case 'DateTime':
+          return value is DateTime ? value : DateTime.tryParse(value);
         {{#models}}
           {{#model}}
         case '{{{classname}}}':
diff --git a/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart b/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
index 79977d854b6..ce5560f03f0 100644
--- a/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
+++ b/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
@@ -190,6 +190,8 @@ class ApiClient {
           }
           final valueString = '$value'.toLowerCase();
           return valueString == 'true' || valueString == '1';
+        case 'DateTime':
+          return value is DateTime ? value : DateTime.tryParse(value);
         case 'ApiResponse':
           return ApiResponse.fromJson(value);
         case 'Category':
diff --git a/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart b/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart
index 65fc8807797..94a25909e6d 100644
--- a/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart
+++ b/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart
@@ -190,6 +190,8 @@ class ApiClient {
           }
           final valueString = '$value'.toLowerCase();
           return valueString == 'true' || valueString == '1';
+        case 'DateTime':
+          return value is DateTime ? value : DateTime.tryParse(value);
         case 'AdditionalPropertiesClass':
           return AdditionalPropertiesClass.fromJson(value);
         case 'AllOfWithSingleRef':