diff --git a/config.pbtxt b/config.pbtxt
index f8b3301..f71f506 100644
--- a/config.pbtxt
+++ b/config.pbtxt
@@ -4,6 +4,11 @@ platform: "tensorflow_graphdef"
 max_batch_size: 0
 
 input [
+  {
+    name: "fail-test"
+    data_type: TYPE_STRING
+    dims: [ -1 ]
+  }
 ]
 
 output [