diff --git a/config.pbtxt b/config.pbtxt
index 1476d27..34c3f9c 100644
--- a/config.pbtxt
+++ b/config.pbtxt
@@ -6,7 +6,7 @@ max_batch_size: 0
 input [
   {
     name: "INPUT"
-    data_type: TYPE_STRING
+    data_type: TYPE_BYTES
     dims: [ 1 ]
   }
 ]
@@ -14,7 +14,7 @@ input [
 output [
   {
     name: "OUTPUT"
-    data_type: TYPE_STRING
+    data_type: TYPE_BYTES
     dims: [ 1 ]
   }
 ]