diff --git a/modules/openapi-generator/src/main/resources/cpp-ue4/api-source.mustache b/modules/openapi-generator/src/main/resources/cpp-ue4/api-source.mustache
index d2821b2daaa..8d0efb6a1d9 100644
--- a/modules/openapi-generator/src/main/resources/cpp-ue4/api-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-ue4/api-source.mustache
@@ -56,6 +56,7 @@ void {{classname}}::SetHttpRetryManager(FHttpRetrySystem::FManager& InRetryManag
 
 FHttpRetrySystem::FManager& {{classname}}::GetHttpRetryManager()
 {
+	checkf(RetryManager, TEXT("{{classname}}: RetryManager is null.  You may have meant to set it with SetHttpRetryManager first, or you may not be using a custom RetryManager at all."))
 	return *RetryManager;
 }
 
diff --git a/samples/client/petstore/cpp-ue4/Private/OpenAPIPetApi.cpp b/samples/client/petstore/cpp-ue4/Private/OpenAPIPetApi.cpp
index ec0444e643c..3e52679fc3e 100644
--- a/samples/client/petstore/cpp-ue4/Private/OpenAPIPetApi.cpp
+++ b/samples/client/petstore/cpp-ue4/Private/OpenAPIPetApi.cpp
@@ -65,6 +65,7 @@ void OpenAPIPetApi::SetHttpRetryManager(FHttpRetrySystem::FManager& InRetryManag
 
 FHttpRetrySystem::FManager& OpenAPIPetApi::GetHttpRetryManager()
 {
+	checkf(RetryManager, TEXT("OpenAPIPetApi: RetryManager is null.  You may have meant to set it with SetHttpRetryManager first, or you may not be using a custom RetryManager at all."))
 	return *RetryManager;
 }
 
diff --git a/samples/client/petstore/cpp-ue4/Private/OpenAPIStoreApi.cpp b/samples/client/petstore/cpp-ue4/Private/OpenAPIStoreApi.cpp
index 1c5935b0867..04ee754d255 100644
--- a/samples/client/petstore/cpp-ue4/Private/OpenAPIStoreApi.cpp
+++ b/samples/client/petstore/cpp-ue4/Private/OpenAPIStoreApi.cpp
@@ -65,6 +65,7 @@ void OpenAPIStoreApi::SetHttpRetryManager(FHttpRetrySystem::FManager& InRetryMan
 
 FHttpRetrySystem::FManager& OpenAPIStoreApi::GetHttpRetryManager()
 {
+	checkf(RetryManager, TEXT("OpenAPIStoreApi: RetryManager is null.  You may have meant to set it with SetHttpRetryManager first, or you may not be using a custom RetryManager at all."))
 	return *RetryManager;
 }
 
diff --git a/samples/client/petstore/cpp-ue4/Private/OpenAPIUserApi.cpp b/samples/client/petstore/cpp-ue4/Private/OpenAPIUserApi.cpp
index 55b34981cb5..cc231f0be31 100644
--- a/samples/client/petstore/cpp-ue4/Private/OpenAPIUserApi.cpp
+++ b/samples/client/petstore/cpp-ue4/Private/OpenAPIUserApi.cpp
@@ -65,6 +65,7 @@ void OpenAPIUserApi::SetHttpRetryManager(FHttpRetrySystem::FManager& InRetryMana
 
 FHttpRetrySystem::FManager& OpenAPIUserApi::GetHttpRetryManager()
 {
+	checkf(RetryManager, TEXT("OpenAPIUserApi: RetryManager is null.  You may have meant to set it with SetHttpRetryManager first, or you may not be using a custom RetryManager at all."))
 	return *RetryManager;
 }