diff --git a/src/GraphQL.Client/GraphQLHttpClient.cs b/src/GraphQL.Client/GraphQLHttpClient.cs
index 584bd65a..af63a5ec 100644
--- a/src/GraphQL.Client/GraphQLHttpClient.cs
+++ b/src/GraphQL.Client/GraphQLHttpClient.cs
@@ -152,9 +152,9 @@ private async Task<GraphQLHttpResponse<TResponse>> SendAPQHttpRequestAsync<TResp
 
         var response = await SendHttpRequestAsync<TResponse>(request, cancellationToken);
 
-        if (useAPQ && response.Errors?.Length > 0)
+        if (useAPQ)
         {
-            if (response.Errors.Any(error => string.Equals(error.Message, "PersistedQueryNotFound", StringComparison.CurrentCultureIgnoreCase)))
+            if (response.Errors?.Any(error => string.Equals(error.Message, "PersistedQueryNotFound", StringComparison.CurrentCultureIgnoreCase)) == true)
             {
                 // GraphQL server supports APQ!
 
diff --git a/src/GraphQL.Client/GraphQLHttpClientOptions.cs b/src/GraphQL.Client/GraphQLHttpClientOptions.cs
index 2544847c..31d55960 100644
--- a/src/GraphQL.Client/GraphQLHttpClientOptions.cs
+++ b/src/GraphQL.Client/GraphQLHttpClientOptions.cs
@@ -114,6 +114,6 @@ public static bool DefaultIsValidResponseToDeserialize(HttpResponseMessage r)
     public Func<IGraphQLHttpResponse, bool> DisableAPQ { get; set; } = response =>
     {
         return ((int)response.StatusCode >= 400 && (int)response.StatusCode < 600) ||
-                response.Errors.Any(error => string.Equals(error.Message, "PersistedQueryNotSupported"));
+                response.Errors?.Any(error => string.Equals(error.Message, "PersistedQueryNotSupported", StringComparison.CurrentCultureIgnoreCase)) == true;
     };
 }