diff --git a/src/Data/NumIdr/Scalar.idr b/src/Data/NumIdr/Scalar.idr
index a6a0ca9..2e34740 100644
--- a/src/Data/NumIdr/Scalar.idr
+++ b/src/Data/NumIdr/Scalar.idr
@@ -27,6 +27,5 @@ unwrap = index 0 . getPrim
 
 
 export
-Num a => Mult (Scalar a) (Scalar a) where
-  Result = Scalar a
+Num a => Mult (Scalar a) (Scalar a) (Scalar a) where
   (*.) = (*)