diff --git a/deferred_division/src/ratio.rs b/deferred_division/src/ratio.rs
index c5abad4..edc386e 100644
--- a/deferred_division/src/ratio.rs
+++ b/deferred_division/src/ratio.rs
@@ -86,6 +86,21 @@ macro_rules! impl_operator {
 				}
 			}
 		}
+		impl<Num,Den,Lhs> core::ops::$trait<$struct<Num,Den>> for Lhs
+			where
+				Den:Copy,
+				Lhs:Mul<Den>,
+				<Lhs as Mul<Den>>::Output:core::ops::$trait<Num>,
+		{
+			type Output=$struct<<<Lhs as Mul<Den>>::Output as core::ops::$trait<Num>>::Output,Den>;
+
+			fn $method(self,rhs:$struct<Num,Den>)->Self::Output{
+				$struct{
+					num:self.mul(rhs.den).$method(rhs.num),
+					den:rhs.den,
+				}
+			}
+		}
 	};
 }
 macro_rules! impl_assign_operator{