diff --git a/src/Grpc.AspNetCore.Server/Model/Internal/ServiceRouteBuilder.cs b/src/Grpc.AspNetCore.Server/Model/Internal/ServiceRouteBuilder.cs
index 42ee0cce1..6f54b56b8 100644
--- a/src/Grpc.AspNetCore.Server/Model/Internal/ServiceRouteBuilder.cs
+++ b/src/Grpc.AspNetCore.Server/Model/Internal/ServiceRouteBuilder.cs
@@ -131,19 +131,20 @@ internal static void CreateUnimplementedEndpoints(
 
         private static void CreateUnimplementedEndpoint(IEndpointRouteBuilder endpointRouteBuilder, string pattern, string displayName, RequestDelegate requestDelegate)
         {
-            var routePattern = RoutePatternFactory.Parse(pattern, defaults: null, new { contentType = GrpcContentTypeConstraint.Instance });
+            var routePattern = RoutePatternFactory.Parse(pattern, defaults: null, new { contentType = GrpcUnimplementedConstraint.Instance });
             var endpointBuilder = endpointRouteBuilder.Map(routePattern, requestDelegate);
 
             endpointBuilder.Add(ep =>
             {
                 ep.DisplayName = $"gRPC - {displayName}";
-                ep.Metadata.Add(new HttpMethodMetadata(new[] { "POST" }));
+                // Don't add POST metadata here. It will return 405 status for other HTTP methods which isn't
+                // what we want. That check is made in a constraint instead.
             });
         }
 
-        private class GrpcContentTypeConstraint : IRouteConstraint
+        private class GrpcUnimplementedConstraint : IRouteConstraint
         {
-            public static readonly GrpcContentTypeConstraint Instance = new GrpcContentTypeConstraint();
+            public static readonly GrpcUnimplementedConstraint Instance = new GrpcUnimplementedConstraint();
 
             public bool Match(HttpContext httpContext, IRouter route, string routeKey, RouteValueDictionary values, RouteDirection routeDirection)
             {
@@ -152,10 +153,15 @@ public bool Match(HttpContext httpContext, IRouter route, string routeKey, Route
                     return false;
                 }
 
+                if (!HttpMethods.IsPost(httpContext.Request.Method))
+                {
+                    return false;
+                }
+
                 return GrpcProtocolHelpers.IsGrpcContentType(httpContext.Request.ContentType);
             }
 
-            private GrpcContentTypeConstraint()
+            private GrpcUnimplementedConstraint()
             {
             }
         }
diff --git a/test/FunctionalTests/Server/UnimplementedTests.cs b/test/FunctionalTests/Server/UnimplementedTests.cs
index f3f4cb8af..5406176db 100644
--- a/test/FunctionalTests/Server/UnimplementedTests.cs
+++ b/test/FunctionalTests/Server/UnimplementedTests.cs
@@ -82,9 +82,11 @@ public async Task HttpContextExtensionMethod_ReturnContextInTrailer()
             response.AssertTrailerStatus(StatusCode.Unimplemented, "Service is unimplemented.");
         }
 
-        [TestCase("application/grpc", HttpStatusCode.OK, StatusCode.Unimplemented)]
-        [TestCase("application/json", (HttpStatusCode)418, null)]
-        public async Task UnimplementedContentType_ReturnUnimplementedForAppGrpc(string contentType, HttpStatusCode httpStatusCode, StatusCode? grpcStatusCode)
+        [TestCase("application/grpc", "POST", HttpStatusCode.OK, StatusCode.Unimplemented)]
+        [TestCase("application/grpc", "GET", (HttpStatusCode)404, null)]
+        [TestCase("application/json", "POST", (HttpStatusCode)404, null)]
+        [TestCase("application/json", "GET", (HttpStatusCode)404, null)]
+        public async Task UnimplementedContentType_ReturnUnimplementedForAppGrpc(string contentType, string httpMethod, HttpStatusCode httpStatusCode, StatusCode? grpcStatusCode)
         {
             // Arrange
             var requestMessage = new HelloRequest
@@ -96,6 +98,7 @@ public async Task UnimplementedContentType_ReturnUnimplementedForAppGrpc(string
             MessageHelpers.WriteMessage(requestStream, requestMessage);
 
             var httpRequest = GrpcHttpHelper.Create("HasMapped/Extra");
+            httpRequest.Method = new HttpMethod(httpMethod);
             httpRequest.Content = new StreamContent(requestStream);
             httpRequest.Content.Headers.ContentType = new MediaTypeHeaderValue(contentType);
 
diff --git a/testassets/FunctionalTestsWebsite/Startup.cs b/testassets/FunctionalTestsWebsite/Startup.cs
index f9f003ccd..3b8a685c4 100644
--- a/testassets/FunctionalTestsWebsite/Startup.cs
+++ b/testassets/FunctionalTestsWebsite/Startup.cs
@@ -133,12 +133,6 @@ public void Configure(IApplicationBuilder app)
 
                 endpoints.DataSources.Add(endpoints.ServiceProvider.GetRequiredService<DynamicEndpointDataSource>());
 
-                endpoints.Map("{FirstSegment}/{SecondSegment}", context =>
-                {
-                    context.Response.StatusCode = StatusCodes.Status418ImATeapot;
-                    return Task.CompletedTask;
-                });
-
                 endpoints.MapGet("/generateJwtToken", context =>
                 {
                     return context.Response.WriteAsync(GenerateJwtToken());