diff --git a/src/rational.rs b/src/rational.rs
index b3dc3ac..2f1100a 100644
--- a/src/rational.rs
+++ b/src/rational.rs
@@ -52,28 +52,21 @@ impl<T: Unsigned> Frac<T> {
     }
 }
 
-macro_rules! impl_mul {
-    ($( $Type: ty ),* ) => {
-        $(
-            impl Mul for Frac<$Type> {
-                type Output = Self;
+impl<T: Unsigned + Mul<Output = T>> Mul for Frac<T> {
+    type Output = Self;
 
-                fn mul(self, rhs: Self) -> Self {
-                    let numer = self.numer * rhs.numer;
-                    let denom = self.denom * rhs.denom;
+    fn mul(self, rhs: Self) -> Self {
+        let numer = self.numer * rhs.numer;
+        let denom = self.denom * rhs.denom;
 
-                    // Figure out the sign
-                    if self.sign != rhs.sign {
-                        Self::new_neg(numer, denom)
-                    } else {
-                        Self::new(numer, denom)
-                    }
-                }
-            }
-        )*
-    };
+        // Figure out the sign
+        if self.sign != rhs.sign {
+            Self::new_neg(numer, denom)
+        } else {
+            Self::new(numer, denom)
+        }
+    }
 }
-impl_mul!(u8, u16, u32, u64, usize, u128);
 
 impl<T: Unsigned> Neg for Frac<T> {
     type Output = Self;