--- a/devtools/shared/client/main.js
+++ b/devtools/shared/client/main.js
@@ -2859,17 +2859,19 @@ ArrayBufferClient.prototype = {
   },
   get _transport() {
     return this._client._transport;
   },
 
   valid: true,
 
   slice: DebuggerClient.requester({
-    type: "slice"
+    type: "slice",
+    start: arg(0),
+    count: arg(1)
   }),
 };
 
 /**
  * A LongStringClient provides a way to access "very long" strings from the
  * debugger server.
  *
  * @param client DebuggerClient