diff --git a/compiler/rustc_middle/src/mir/interpret/mod.rs b/compiler/rustc_middle/src/mir/interpret/mod.rs
index 4e95e600b5ab9..26ff9b0ac60ad 100644
--- a/compiler/rustc_middle/src/mir/interpret/mod.rs
+++ b/compiler/rustc_middle/src/mir/interpret/mod.rs
@@ -222,9 +222,8 @@ impl<'s> AllocDecodingSession<'s> {
 
         // Check the decoding state to see if it's already decoded or if we should
         // decode it here.
+        let mut entry = self.state.decoding_state[idx].lock();
         let alloc_id = {
-            let mut entry = self.state.decoding_state[idx].lock();
-
             match *entry {
                 State::Done(alloc_id) => {
                     return alloc_id;
@@ -317,9 +316,7 @@ impl<'s> AllocDecodingSession<'s> {
             }
         });
 
-        self.state.decoding_state[idx].with_lock(|entry| {
-            *entry = State::Done(alloc_id);
-        });
+        *entry = State::Done(alloc_id);
 
         alloc_id
     }