diff --git a/wgpu-core/src/device/queue.rs b/wgpu-core/src/device/queue.rs
index 494e42e508..dc0335a35a 100644
--- a/wgpu-core/src/device/queue.rs
+++ b/wgpu-core/src/device/queue.rs
@@ -816,6 +816,8 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             callbacks
         };
 
+        // the map callbacks should execute with nothing locked!
+        drop(token);
         super::fire_map_callbacks(callbacks);
 
         Ok(())