diff --git a/src/hz_format.erl b/src/hz_format.erl
index 859f3f8..cbce80a 100644
--- a/src/hz_format.erl
+++ b/src/hz_format.erl
@@ -552,7 +552,7 @@ calc(G, P) ->
     case calc(gaju, G, 0) of
         {ok, Gajus} ->
             case calc(puck, P, 0) of
-                {ok, Pucks} -> Gajus + Pucks;
+                {ok, Pucks} -> {ok, Gajus + Pucks};
                 error       -> error
             end;
         error ->