diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index 263b1449de156..a32a0271adfe7 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -883,7 +883,10 @@ impl<T, A: Allocator> Rc<T, A> {
     #[cfg(not(no_global_oom_handling))]
     #[unstable(feature = "allocator_api", issue = "32838")]
     #[inline]
-    pub fn pin_in(value: T, alloc: A) -> Pin<Self> {
+    pub fn pin_in(value: T, alloc: A) -> Pin<Self>
+    where
+        A: 'static,
+    {
         unsafe { Pin::new_unchecked(Rc::new_in(value, alloc)) }
     }
 
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index 5273b3cb2dafa..c389066e6b62e 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -801,7 +801,10 @@ impl<T, A: Allocator> Arc<T, A> {
     #[cfg(not(no_global_oom_handling))]
     #[unstable(feature = "allocator_api", issue = "32838")]
     #[inline]
-    pub fn pin_in(data: T, alloc: A) -> Pin<Arc<T, A>> {
+    pub fn pin_in(data: T, alloc: A) -> Pin<Arc<T, A>>
+    where
+        A: 'static,
+    {
         unsafe { Pin::new_unchecked(Arc::new_in(data, alloc)) }
     }
 
@@ -809,7 +812,10 @@ impl<T, A: Allocator> Arc<T, A> {
     /// fails.
     #[inline]
     #[unstable(feature = "allocator_api", issue = "32838")]
-    pub fn try_pin_in(data: T, alloc: A) -> Result<Pin<Arc<T, A>>, AllocError> {
+    pub fn try_pin_in(data: T, alloc: A) -> Result<Pin<Arc<T, A>>, AllocError>
+    where
+        A: 'static,
+    {
         unsafe { Ok(Pin::new_unchecked(Arc::try_new_in(data, alloc)?)) }
     }