diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index 1ef3cc0b810..0008790c973 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -5453,7 +5453,7 @@ impl ${name}Cast {
     #[inline(always)]
     pub fn to_ref<'a, T: ${toBound}+Reflectable>(base: JSRef<'a, T>) -> Option<JSRef<'a, ${name}>> {
         match base.${checkFn}() {
-            true => unsafe { Some(base.transmute()) },
+            true => Some(unsafe { mem::transmute(base) }),
             false => None
         }
     }
@@ -5461,7 +5461,7 @@ impl ${name}Cast {
     #[inline(always)]
     pub fn to_borrowed_ref<'a, 'b, T: ${toBound}+Reflectable>(base: &'a JSRef<'b, T>) -> Option<&'a JSRef<'b, ${name}>> {
         match base.${checkFn}() {
-            true => unsafe { Some(base.transmute_borrowed()) },
+            true => Some(unsafe { mem::transmute(base) }),
             false => None
         }
     }
@@ -5479,22 +5479,20 @@ impl ${name}Cast {
 
     #[inline(always)]
     pub fn to_temporary<T: ${toBound}+Reflectable>(base: Temporary<T>) -> Option<Temporary<${name}>> {
-        let base = base.root();
-        let base = base.r();
-        match base.${checkFn}() {
-            true => Some(Temporary::from_rooted(unsafe { base.transmute() })),
+        match base.root().r().${checkFn}() {
+            true => Some(unsafe { mem::transmute(base) }),
             false => None
         }
     }
 
     #[inline(always)]
     pub fn from_ref<'a, T: ${fromBound}+Reflectable>(derived: JSRef<'a, T>) -> JSRef<'a, ${name}> {
-        unsafe { derived.transmute() }
+        unsafe { mem::transmute(derived) }
     }
 
     #[inline(always)]
     pub fn from_borrowed_ref<'a, 'b, T: ${fromBound}+Reflectable>(derived: &'a JSRef<'b, T>) -> &'a JSRef<'b, ${name}> {
-        unsafe { derived.transmute_borrowed() }
+        unsafe { mem::transmute(derived) }
     }
 
     #[inline(always)]
@@ -5505,7 +5503,7 @@ impl ${name}Cast {
 
     #[inline(always)]
     pub fn from_temporary<T: ${fromBound}+Reflectable>(derived: Temporary<T>) -> Temporary<${name}> {
-        unsafe { derived.transmute() }
+        unsafe { mem::transmute(derived) }
     }
 
     #[inline(always)]
diff --git a/components/script/dom/bindings/js.rs b/components/script/dom/bindings/js.rs
index 6b3ce4a555c..cc36600318c 100644
--- a/components/script/dom/bindings/js.rs
+++ b/components/script/dom/bindings/js.rs
@@ -186,13 +186,6 @@ impl<T: Reflectable> Temporary<T> {
     unsafe fn inner(&self) -> JS<T> {
         self.inner.clone()
     }
-
-    /// Returns `self` as a `Temporary` of another type. For use by
-    /// `InheritTypes` only.
-    //XXXjdm It would be lovely if this could be private.
-    pub unsafe fn transmute<To>(self) -> Temporary<To> {
-        mem::transmute(self)
-    }
 }
 
 /// A traced reference to a DOM object. Must only be used as a field in other
@@ -438,13 +431,6 @@ impl<T: Reflectable> LayoutJS<T> {
     }
 }
 
-impl<From> JS<From> {
-    /// Return `self` as a `JS` of another type.
-    pub unsafe fn transmute_copy<To>(&self) -> JS<To> {
-        mem::transmute_copy(self)
-    }
-}
-
 impl<From> LayoutJS<From> {
     /// Return `self` as a `LayoutJS` of another type.
     pub unsafe fn transmute_copy<To>(&self) -> LayoutJS<To> {
@@ -748,18 +734,6 @@ impl<'a, 'b, T> PartialEq<JSRef<'b, T>> for JSRef<'a, T> {
 }
 
 impl<'a,T> JSRef<'a,T> {
-    /// Return `self` as a `JSRef` of another type.
-    //XXXjdm It would be lovely if this could be private.
-    pub unsafe fn transmute<To>(self) -> JSRef<'a, To> {
-        mem::transmute(self)
-    }
-
-    /// Return `self` as a borrowed reference to a `JSRef` of another type.
-    // FIXME(zwarich): It would be nice to get rid of this entirely.
-    pub unsafe fn transmute_borrowed<'b, To>(&'b self) -> &'b JSRef<'a, To> {
-        mem::transmute(self)
-    }
-
     /// Return an unrooted `JS<T>` for the inner pointer.
     pub fn unrooted(&self) -> JS<T> {
         JS {