diff --git a/src/gd_v_call.erl b/src/gd_v_call.erl
index 7f3f084..0ed41b5 100644
--- a/src/gd_v_call.erl
+++ b/src/gd_v_call.erl
@@ -216,7 +216,12 @@ return_sizer(Parent, J, FunIlk, ReturnType) ->
 
 
 call_param_sizer(Frame, J) ->
-    {ok, Height} = hz:top_height(),
+    case hz:top_height() of
+        {ok, Height} -> call_param_sizer(Frame, J, Height);
+        Error        -> handle_troubling(State, Error)
+    end.
+
+call_param_sizer(Frame, J, Height) ->
     DefTTL = Height + 10000,
     DefGasP = hz:min_gas_price(),
     DefGas = 5000000,