diff --git a/src/ApiCodeGenerator.OpenApi/ContentGeneratorBase.cs b/src/ApiCodeGenerator.OpenApi/ContentGeneratorBase.cs
index e67ba8e..ce0a599 100644
--- a/src/ApiCodeGenerator.OpenApi/ContentGeneratorBase.cs
+++ b/src/ApiCodeGenerator.OpenApi/ContentGeneratorBase.cs
@@ -120,19 +120,12 @@ protected static async Task<OpenApiDocument> ReadAndProcessOpenApiDocument(Gener
             var documentStr = context.DocumentReader!.ReadToEnd();
             documentStr = InvokePreprocessors<string>(documentStr, context.Preprocessors, context.DocumentPath);
 
-            var openApiDocument = IsYaml()
+            var openApiDocument = !(documentStr.StartsWith("{") && documentStr.EndsWith("}"))
                 ? await OpenApiYamlDocument.FromYamlAsync(documentStr)
                 : await OpenApiDocument.FromJsonAsync(documentStr);
 
             openApiDocument = InvokePreprocessors<OpenApiDocument>(openApiDocument, context.Preprocessors, context.DocumentPath);
             return openApiDocument;
-
-            bool IsYaml()
-            {
-                return
-                    (context.DocumentPath is not null && (context.DocumentPath.EndsWith("yml") || context.DocumentPath.EndsWith("yaml")))
-                    || !(documentStr.StartsWith("{") && documentStr.EndsWith("}"));
-            }
         }
 
     }
diff --git a/test/ApiCodeGenerator.OpenApi.Tests/ContentGeneratorFactoryTests.cs b/test/ApiCodeGenerator.OpenApi.Tests/ContentGeneratorFactoryTests.cs
index b2a2852..160b885 100644
--- a/test/ApiCodeGenerator.OpenApi.Tests/ContentGeneratorFactoryTests.cs
+++ b/test/ApiCodeGenerator.OpenApi.Tests/ContentGeneratorFactoryTests.cs
@@ -128,14 +128,12 @@ public async Task LoadOpenApiDocument_WithModelPreprocess()
             Assert.That(sch, Is.EqualTo("{\"$schema\":\"http://json-schema.org/draft-04/schema#\",\"additionalProperties\":false,\"properties\":{\"processedModel\":{}}}"));
         }
 
-        [TestCase(null)]
-        [TestCase("testSchem.yaml")]
-        public async Task LoadOpenApiDocument_FromYaml(string? documentPath)
+        [Test]
+        public async Task LoadOpenApiDocument_FromYaml()
         {
             var context = CreateContext(new());
             var schemaText = await File.ReadAllTextAsync(TestHelpers.GetSwaggerPath("testSchema.yaml"));
             context.DocumentReader = new StringReader(schemaText);
-            context.DocumentPath = documentPath;
 
             var gen = (CSharpClientContentGenerator)await CSharpClientContentGenerator.CreateAsync(context);