diff --git a/src/scale.rs b/src/scale.rs
index 983b366..b98a46d 100644
--- a/src/scale.rs
+++ b/src/scale.rs
@@ -243,6 +243,18 @@ impl<T, Src, Dst> Scale<T, Src, Dst> {
         let one: T = One::one();
         Scale::new(one / self.0)
     }
+
+    /// Returns the same transform with a different source unit.
+    #[inline]
+    pub fn with_source<NewSrc>(self) -> Scale<T, NewSrc, Dst> {
+        Scale::new(self.0)
+    }
+
+    /// Returns the same transform with a different destination unit.
+    #[inline]
+    pub fn with_destination<NewDst>(self) -> Scale<T, Src, NewDst> {
+        Scale::new(self.0)
+    }
 }
 
 impl<T: PartialOrd, Src, Dst> Scale<T, Src, Dst> {