diff --git a/src/StreamJsonRpc/JsonRpc.cs b/src/StreamJsonRpc/JsonRpc.cs
index ea125ce73..42f32b141 100644
--- a/src/StreamJsonRpc/JsonRpc.cs
+++ b/src/StreamJsonRpc/JsonRpc.cs
@@ -1575,7 +1575,7 @@ protected async Task<TResult> InvokeCoreAsync<TResult>(RequestId id, string targ
             }
             else
             {
-                throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, Resources.ResponseUnexpectedFormat, JsonConvert.SerializeObject(response)));
+                throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, Resources.ResponseUnexpectedFormat, response?.GetType().FullName ?? "(null)"));
             }
         }
         else
diff --git a/src/StreamJsonRpc/Resources.resx b/src/StreamJsonRpc/Resources.resx
index f61ffd63e..e87e9b73a 100644
--- a/src/StreamJsonRpc/Resources.resx
+++ b/src/StreamJsonRpc/Resources.resx
@@ -288,8 +288,8 @@
     <value>Failed to serialize the response.</value>
   </data>
   <data name="ResponseUnexpectedFormat" xml:space="preserve">
-    <value>Response is in an unexpected format.  Only error and result are supported: {0}</value>
-    <comment>{0} is the response message.</comment>
+    <value>Response is in an unexpected format.  Only error and result are supported, but received type: {0}</value>
+    <comment>{0} is the response object type.</comment>
   </data>
   <data name="RpcMarshalableDuplicatedOptionalInterface" xml:space="preserve">
     <value>Optional interface declarations should be unique. {0} has the same optional interface declared multiple times.</value>