diff --git a/envoy/grpc/async_client_manager.h b/envoy/grpc/async_client_manager.h
index 629873e9f16d..aa99f2c23a6e 100644
--- a/envoy/grpc/async_client_manager.h
+++ b/envoy/grpc/async_client_manager.h
@@ -34,6 +34,8 @@ using AsyncClientFactoryPtr = std::unique_ptr<AsyncClientFactory>;
 
 class GrpcServiceConfigWithHashKey {
 public:
+  GrpcServiceConfigWithHashKey() = default;
+
   explicit GrpcServiceConfigWithHashKey(const envoy::config::core::v3::GrpcService& config)
       : config_(config), pre_computed_hash_(Envoy::MessageUtil::hash(config)){};
 
@@ -53,9 +55,14 @@ class GrpcServiceConfigWithHashKey {
 
   const envoy::config::core::v3::GrpcService& config() const { return config_; }
 
+  void setConfig(const envoy::config::core::v3::GrpcService g) {
+    config_ = g;
+    pre_computed_hash_ = Envoy::MessageUtil::hash(g);
+  }
+
 private:
-  const envoy::config::core::v3::GrpcService config_;
-  const std::size_t pre_computed_hash_;
+  envoy::config::core::v3::GrpcService config_;
+  std::size_t pre_computed_hash_;
 };
 
 // Singleton gRPC client manager. Grpc::AsyncClientManager can be used to create per-service
diff --git a/source/extensions/filters/http/ext_proc/BUILD b/source/extensions/filters/http/ext_proc/BUILD
index 2c2397d6d304..484395f170d3 100644
--- a/source/extensions/filters/http/ext_proc/BUILD
+++ b/source/extensions/filters/http/ext_proc/BUILD
@@ -56,6 +56,7 @@ envoy_cc_library(
     name = "client_interface",
     hdrs = ["client.h"],
     deps = [
+        "//envoy/grpc:async_client_manager_interface",
         "//envoy/grpc:status",
         "//envoy/stream_info:stream_info_interface",
         "@envoy_api//envoy/config/core/v3:pkg_cc_proto",
diff --git a/source/extensions/filters/http/ext_proc/client.h b/source/extensions/filters/http/ext_proc/client.h
index e4c7dba2fef3..25594b3748e4 100644
--- a/source/extensions/filters/http/ext_proc/client.h
+++ b/source/extensions/filters/http/ext_proc/client.h
@@ -4,6 +4,7 @@
 
 #include "envoy/common/pure.h"
 #include "envoy/config/core/v3/grpc_service.pb.h"
+#include "envoy/grpc/async_client_manager.h"
 #include "envoy/grpc/status.h"
 #include "envoy/service/ext_proc/v3/external_processor.pb.h"
 #include "envoy/stream_info/stream_info.h"
@@ -38,9 +39,10 @@ class ExternalProcessorCallbacks {
 class ExternalProcessorClient {
 public:
   virtual ~ExternalProcessorClient() = default;
-  virtual ExternalProcessorStreamPtr start(ExternalProcessorCallbacks& callbacks,
-                                           const envoy::config::core::v3::GrpcService& grpc_service,
-                                           const StreamInfo::StreamInfo& stream_info) PURE;
+  virtual ExternalProcessorStreamPtr
+  start(ExternalProcessorCallbacks& callbacks,
+        const Grpc::GrpcServiceConfigWithHashKey& config_with_hash_key,
+        const StreamInfo::StreamInfo& stream_info) PURE;
 };
 
 using ExternalProcessorClientPtr = std::unique_ptr<ExternalProcessorClient>;
diff --git a/source/extensions/filters/http/ext_proc/client_impl.cc b/source/extensions/filters/http/ext_proc/client_impl.cc
index 22d970929b2d..80ccd31189db 100644
--- a/source/extensions/filters/http/ext_proc/client_impl.cc
+++ b/source/extensions/filters/http/ext_proc/client_impl.cc
@@ -13,10 +13,10 @@ ExternalProcessorClientImpl::ExternalProcessorClientImpl(Grpc::AsyncClientManage
 
 ExternalProcessorStreamPtr
 ExternalProcessorClientImpl::start(ExternalProcessorCallbacks& callbacks,
-                                   const envoy::config::core::v3::GrpcService& grpc_service,
+                                   const Grpc::GrpcServiceConfigWithHashKey& config_with_hash_key,
                                    const StreamInfo::StreamInfo& stream_info) {
   Grpc::AsyncClient<ProcessingRequest, ProcessingResponse> grpcClient(
-      client_manager_.getOrCreateRawAsyncClient(grpc_service, scope_, true));
+      client_manager_.getOrCreateRawAsyncClientWithHashKey(config_with_hash_key, scope_, true));
   return ExternalProcessorStreamImpl::create(std::move(grpcClient), callbacks, stream_info);
 }
 
diff --git a/source/extensions/filters/http/ext_proc/client_impl.h b/source/extensions/filters/http/ext_proc/client_impl.h
index 90f00fa0baa9..45c86fc9da5c 100644
--- a/source/extensions/filters/http/ext_proc/client_impl.h
+++ b/source/extensions/filters/http/ext_proc/client_impl.h
@@ -27,7 +27,7 @@ class ExternalProcessorClientImpl : public ExternalProcessorClient {
   ExternalProcessorClientImpl(Grpc::AsyncClientManager& client_manager, Stats::Scope& scope);
 
   ExternalProcessorStreamPtr start(ExternalProcessorCallbacks& callbacks,
-                                   const envoy::config::core::v3::GrpcService& grpc_service,
+                                   const Grpc::GrpcServiceConfigWithHashKey& config_with_hash_key,
                                    const StreamInfo::StreamInfo& stream_info) override;
 
 private:
diff --git a/source/extensions/filters/http/ext_proc/ext_proc.cc b/source/extensions/filters/http/ext_proc/ext_proc.cc
index f4b56b93a515..b0e16cba79bb 100644
--- a/source/extensions/filters/http/ext_proc/ext_proc.cc
+++ b/source/extensions/filters/http/ext_proc/ext_proc.cc
@@ -160,7 +160,7 @@ Filter::StreamOpenState Filter::openStream() {
   }
   if (!stream_) {
     ENVOY_LOG(debug, "Opening gRPC stream to external processor");
-    stream_ = client_->start(*this, grpc_service_, decoder_callbacks_->streamInfo());
+    stream_ = client_->start(*this, config_with_hash_key_, decoder_callbacks_->streamInfo());
     if (processing_complete_) {
       // Stream failed while starting and either onGrpcError or onGrpcClose was already called
       // Asserts that `stream_` is nullptr since it is not valid to be used any further
@@ -874,6 +874,7 @@ void Filter::mergePerRouteConfig() {
   if (merged_config->grpcService()) {
     ENVOY_LOG(trace, "Setting new GrpcService from per-route configuration");
     grpc_service_ = *merged_config->grpcService();
+    config_with_hash_key_.setConfig(*merged_config->grpcService());
   }
 }
 
diff --git a/source/extensions/filters/http/ext_proc/ext_proc.h b/source/extensions/filters/http/ext_proc/ext_proc.h
index 9a2467c27989..9b74867aba47 100644
--- a/source/extensions/filters/http/ext_proc/ext_proc.h
+++ b/source/extensions/filters/http/ext_proc/ext_proc.h
@@ -246,7 +246,8 @@ class Filter : public Logger::Loggable<Logger::Id::ext_proc>,
   Filter(const FilterConfigSharedPtr& config, ExternalProcessorClientPtr&& client,
          const envoy::config::core::v3::GrpcService& grpc_service)
       : config_(config), client_(std::move(client)), stats_(config->stats()),
-        grpc_service_(grpc_service), decoding_state_(*this, config->processingMode()),
+        grpc_service_(grpc_service), config_with_hash_key_(grpc_service),
+        decoding_state_(*this, config->processingMode()),
         encoding_state_(*this, config->processingMode()) {}
 
   const FilterConfig& config() const { return *config_; }
@@ -304,6 +305,7 @@ class Filter : public Logger::Loggable<Logger::Id::ext_proc>,
   ExtProcFilterStats stats_;
   ExtProcLoggingInfo* logging_info_;
   envoy::config::core::v3::GrpcService grpc_service_;
+  Grpc::GrpcServiceConfigWithHashKey config_with_hash_key_;
 
   // The state of the filter on both the encoding and decoding side.
   DecodingProcessorState decoding_state_;
diff --git a/test/extensions/filters/http/ext_proc/client_test.cc b/test/extensions/filters/http/ext_proc/client_test.cc
index 1099ae88fc54..63bd95f2b1aa 100644
--- a/test/extensions/filters/http/ext_proc/client_test.cc
+++ b/test/extensions/filters/http/ext_proc/client_test.cc
@@ -30,8 +30,9 @@ class ExtProcStreamTest : public testing::Test, public ExternalProcessorCallback
 protected:
   void SetUp() override {
     grpc_service_.mutable_envoy_grpc()->set_cluster_name("test");
+    config_with_hash_key_.setConfig(grpc_service_);
 
-    EXPECT_CALL(client_manager_, getOrCreateRawAsyncClient(_, _, _))
+    EXPECT_CALL(client_manager_, getOrCreateRawAsyncClientWithHashKey(_, _, _))
         .WillOnce(Invoke(this, &ExtProcStreamTest::doFactory));
 
     client_ =
@@ -67,6 +68,7 @@ class ExtProcStreamTest : public testing::Test, public ExternalProcessorCallback
   bool grpc_closed_ = false;
 
   envoy::config::core::v3::GrpcService grpc_service_;
+  Grpc::GrpcServiceConfigWithHashKey config_with_hash_key_;
   ExternalProcessorClientPtr client_;
   Grpc::MockAsyncClientManager client_manager_;
   Grpc::MockAsyncStream stream_;
@@ -77,14 +79,14 @@ class ExtProcStreamTest : public testing::Test, public ExternalProcessorCallback
 };
 
 TEST_F(ExtProcStreamTest, OpenCloseStream) {
-  auto stream = client_->start(*this, grpc_service_, stream_info_);
+  auto stream = client_->start(*this, config_with_hash_key_, stream_info_);
   EXPECT_CALL(stream_, closeStream());
   EXPECT_CALL(stream_, resetStream());
   stream->close();
 }
 
 TEST_F(ExtProcStreamTest, SendToStream) {
-  auto stream = client_->start(*this, grpc_service_, stream_info_);
+  auto stream = client_->start(*this, config_with_hash_key_, stream_info_);
   // Send something and ensure that we get it. Doesn't really matter what.
   EXPECT_CALL(stream_, sendMessageRaw_(_, false));
   ProcessingRequest req;
@@ -95,14 +97,14 @@ TEST_F(ExtProcStreamTest, SendToStream) {
 }
 
 TEST_F(ExtProcStreamTest, SendAndClose) {
-  auto stream = client_->start(*this, grpc_service_, stream_info_);
+  auto stream = client_->start(*this, config_with_hash_key_, stream_info_);
   EXPECT_CALL(stream_, sendMessageRaw_(_, true));
   ProcessingRequest req;
   stream->send(std::move(req), true);
 }
 
 TEST_F(ExtProcStreamTest, ReceiveFromStream) {
-  auto stream = client_->start(*this, grpc_service_, stream_info_);
+  auto stream = client_->start(*this, config_with_hash_key_, stream_info_);
   ASSERT_NE(stream_callbacks_, nullptr);
   // Send something and ensure that we get it. Doesn't really matter what.
   ProcessingResponse resp;
@@ -132,7 +134,7 @@ TEST_F(ExtProcStreamTest, ReceiveFromStream) {
 }
 
 TEST_F(ExtProcStreamTest, StreamClosed) {
-  auto stream = client_->start(*this, grpc_service_, stream_info_);
+  auto stream = client_->start(*this, config_with_hash_key_, stream_info_);
   ASSERT_NE(stream_callbacks_, nullptr);
   EXPECT_FALSE(last_response_);
   EXPECT_FALSE(grpc_closed_);
@@ -145,7 +147,7 @@ TEST_F(ExtProcStreamTest, StreamClosed) {
 }
 
 TEST_F(ExtProcStreamTest, StreamError) {
-  auto stream = client_->start(*this, grpc_service_, stream_info_);
+  auto stream = client_->start(*this, config_with_hash_key_, stream_info_);
   ASSERT_NE(stream_callbacks_, nullptr);
   EXPECT_FALSE(last_response_);
   EXPECT_FALSE(grpc_closed_);
diff --git a/test/extensions/filters/http/ext_proc/filter_test.cc b/test/extensions/filters/http/ext_proc/filter_test.cc
index befcfc7df45b..ecf2893003cd 100644
--- a/test/extensions/filters/http/ext_proc/filter_test.cc
+++ b/test/extensions/filters/http/ext_proc/filter_test.cc
@@ -163,10 +163,13 @@ class HttpFilterTest : public testing::Test {
   }
 
   ExternalProcessorStreamPtr doStart(ExternalProcessorCallbacks& callbacks,
-                                     const envoy::config::core::v3::GrpcService& grpc_service,
+                                     const Grpc::GrpcServiceConfigWithHashKey& config_with_hash_key,
                                      testing::Unused) {
     if (final_expected_grpc_service_.has_value()) {
-      EXPECT_TRUE(TestUtility::protoEqual(final_expected_grpc_service_.value(), grpc_service));
+      EXPECT_TRUE(TestUtility::protoEqual(final_expected_grpc_service_.value(),
+                                          config_with_hash_key.config()));
+      std::cout << final_expected_grpc_service_.value().DebugString();
+      std::cout << config_with_hash_key.config().DebugString();
     }
 
     stream_callbacks_ = &callbacks;
@@ -463,6 +466,7 @@ class HttpFilterTest : public testing::Test {
   }
 
   absl::optional<envoy::config::core::v3::GrpcService> final_expected_grpc_service_;
+  Grpc::GrpcServiceConfigWithHashKey config_with_hash_key_;
   std::unique_ptr<MockClient> client_;
   ExternalProcessorCallbacks* stream_callbacks_ = nullptr;
   ProcessingRequest last_request_;
@@ -2462,6 +2466,7 @@ TEST_F(HttpFilterTest, ProcessingModeResponseHeadersOnlyWithoutCallingDecodeHead
             cb(route_config);
           }));
   final_expected_grpc_service_.emplace(route_proto.overrides().grpc_service());
+  config_with_hash_key_.setConfig(route_proto.overrides().grpc_service());
 
   response_headers_.addCopy(LowerCaseString(":status"), "200");
   response_headers_.addCopy(LowerCaseString("content-type"), "text/plain");
diff --git a/test/extensions/filters/http/ext_proc/mock_server.h b/test/extensions/filters/http/ext_proc/mock_server.h
index f655e977a2e4..5f4dedb90173 100644
--- a/test/extensions/filters/http/ext_proc/mock_server.h
+++ b/test/extensions/filters/http/ext_proc/mock_server.h
@@ -14,7 +14,7 @@ class MockClient : public ExternalProcessorClient {
   MockClient();
   ~MockClient() override;
   MOCK_METHOD(ExternalProcessorStreamPtr, start,
-              (ExternalProcessorCallbacks&, const envoy::config::core::v3::GrpcService&,
+              (ExternalProcessorCallbacks&, const Grpc::GrpcServiceConfigWithHashKey&,
                const StreamInfo::StreamInfo&));
 };
 
diff --git a/test/extensions/filters/http/ext_proc/ordering_test.cc b/test/extensions/filters/http/ext_proc/ordering_test.cc
index ace797afd5fb..035be9801616 100644
--- a/test/extensions/filters/http/ext_proc/ordering_test.cc
+++ b/test/extensions/filters/http/ext_proc/ordering_test.cc
@@ -81,7 +81,7 @@ class OrderingTest : public testing::Test {
 
   // Called by the "start" method on the stream by the filter
   virtual ExternalProcessorStreamPtr doStart(ExternalProcessorCallbacks& callbacks,
-                                             const envoy::config::core::v3::GrpcService&,
+                                             const Grpc::GrpcServiceConfigWithHashKey&,
                                              const StreamInfo::StreamInfo&) {
     stream_callbacks_ = &callbacks;
     auto stream = std::make_unique<MockStream>();
@@ -218,7 +218,7 @@ class OrderingTest : public testing::Test {
 class FastFailOrderingTest : public OrderingTest {
   // All tests using this class have gRPC streams that will fail while being opened.
   ExternalProcessorStreamPtr doStart(ExternalProcessorCallbacks& callbacks,
-                                     const envoy::config::core::v3::GrpcService&,
+                                     const Grpc::GrpcServiceConfigWithHashKey&,
                                      const StreamInfo::StreamInfo&) override {
     callbacks.onGrpcError(Grpc::Status::Internal);
     // Returns nullptr on start stream failure.
diff --git a/test/extensions/filters/http/ext_proc/unit_test_fuzz/ext_proc_unit_test_fuzz.cc b/test/extensions/filters/http/ext_proc/unit_test_fuzz/ext_proc_unit_test_fuzz.cc
index 6bb5e89d272f..984b828e0e02 100644
--- a/test/extensions/filters/http/ext_proc/unit_test_fuzz/ext_proc_unit_test_fuzz.cc
+++ b/test/extensions/filters/http/ext_proc/unit_test_fuzz/ext_proc_unit_test_fuzz.cc
@@ -87,7 +87,7 @@ DEFINE_PROTO_FUZZER(
   EXPECT_CALL(*client, start(_, _, _))
       .WillRepeatedly(Invoke(
           [&](ExternalProcessing::ExternalProcessorCallbacks&,
-              const envoy::config::core::v3::GrpcService&,
+              const Grpc::GrpcServiceConfigWithHashKey&,
               const StreamInfo::StreamInfo&) -> ExternalProcessing::ExternalProcessorStreamPtr {
             auto stream = std::make_unique<MockStream>();
             EXPECT_CALL(*stream, send(_, _))
diff --git a/test/extensions/filters/http/ext_proc/unit_test_fuzz/mocks.h b/test/extensions/filters/http/ext_proc/unit_test_fuzz/mocks.h
index cbfafb5f2473..207b820e21df 100644
--- a/test/extensions/filters/http/ext_proc/unit_test_fuzz/mocks.h
+++ b/test/extensions/filters/http/ext_proc/unit_test_fuzz/mocks.h
@@ -30,7 +30,7 @@ class MockClient : public ExternalProcessing::ExternalProcessorClient {
 
   MOCK_METHOD(ExternalProcessing::ExternalProcessorStreamPtr, start,
               (ExternalProcessing::ExternalProcessorCallbacks & callbacks,
-               const envoy::config::core::v3::GrpcService& grpc_service,
+               const Grpc::GrpcServiceConfigWithHashKey& config_with_hash_key,
                const StreamInfo::StreamInfo& stream_info));
 };