diff --git a/src/liballoc/vec_deque.rs b/src/liballoc/vec_deque.rs
index 055c2d4840a..2068c2c9c5f 100644
--- a/src/liballoc/vec_deque.rs
+++ b/src/liballoc/vec_deque.rs
@@ -2558,7 +2558,7 @@ impl<'a, T> Place<T> for PlaceBack<'a, T> {
 impl<'a, T> InPlace<T> for PlaceBack<'a, T> {
     type Owner = &'a mut T;
 
-    unsafe fn finalize(mut self) -> &'a mut T {
+    unsafe fn finalize(self) -> &'a mut T {
         let head = self.vec_deque.head;
         self.vec_deque.head = self.vec_deque.wrap_add(head, 1);
         &mut *(self.vec_deque.ptr().offset(head as isize))
@@ -2605,7 +2605,7 @@ impl<'a, T> Place<T> for PlaceFront<'a, T> {
 impl<'a, T> InPlace<T> for PlaceFront<'a, T> {
     type Owner = &'a mut T;
 
-    unsafe fn finalize(mut self) -> &'a mut T {
+    unsafe fn finalize(self) -> &'a mut T {
         self.vec_deque.tail = self.vec_deque.wrap_sub(self.vec_deque.tail, 1);
         &mut *(self.vec_deque.ptr().offset(self.vec_deque.tail as isize))
     }
diff --git a/src/libstd/collections/hash/table.rs b/src/libstd/collections/hash/table.rs
index 3844690860b..6f7c5a5de42 100644
--- a/src/libstd/collections/hash/table.rs
+++ b/src/libstd/collections/hash/table.rs
@@ -563,7 +563,7 @@ impl<'t, K, V> FullBucket<K, V, &'t mut RawTable<K, V>> {
     ///
     /// This works similarly to `put`, building an `EmptyBucket` out of the
     /// taken bucket.
-    pub fn take(mut self) -> (EmptyBucket<K, V, &'t mut RawTable<K, V>>, K, V) {
+    pub fn take(self) -> (EmptyBucket<K, V, &'t mut RawTable<K, V>>, K, V) {
         self.table.size -= 1;
 
         unsafe {
diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index 9734bb867f1..16b06424c92 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -529,7 +529,7 @@ impl<'a, 'b> Context<'a, 'b> {
 
     /// Actually builds the expression which the format_args! block will be
     /// expanded to
-    fn into_expr(mut self) -> P<ast::Expr> {
+    fn into_expr(self) -> P<ast::Expr> {
         let mut locals = Vec::new();
         let mut counts = Vec::new();
         let mut pats = Vec::new();