diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index ee83f782f4..9c0f3093e1 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -12,7 +12,7 @@ env:
   CARGO_NET_RETRY: 10
   CI: 1
   RUST_BACKTRACE: short
-  RUSTFLAGS: "-D warnings -W unreachable-pub"
+  RUSTFLAGS: "-D warnings -W unreachable-pub -W rust-2021-compatibility"
   RUSTUP_MAX_RETRIES: 10
 
 jobs:
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index 4c09b2ab19..4ec3e10f49 100644
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -547,10 +547,10 @@ impl InFile<SyntaxToken> {
         self,
         db: &dyn db::AstDatabase,
     ) -> impl Iterator<Item = InFile<SyntaxNode>> + '_ {
-        self.value
-            .parent()
-            .into_iter()
-            .flat_map(move |parent| InFile::new(self.file_id, parent).ancestors_with_macros(db))
+        self.value.parent().into_iter().flat_map({
+            let file_id = self.file_id;
+            move |parent| InFile::new(file_id, parent).ancestors_with_macros(db)
+        })
     }
 }
 
diff --git a/crates/rust-analyzer/src/dispatch.rs b/crates/rust-analyzer/src/dispatch.rs
index 5991e72b5e..609459b7ed 100644
--- a/crates/rust-analyzer/src/dispatch.rs
+++ b/crates/rust-analyzer/src/dispatch.rs
@@ -30,16 +30,18 @@ impl<'a> RequestDispatcher<'a> {
             Some(it) => it,
             None => return Ok(self),
         };
-        let world = panic::AssertUnwindSafe(&mut *self.global_state);
+        let global_state = panic::AssertUnwindSafe(&mut *self.global_state);
 
         let response = panic::catch_unwind(move || {
+            let _ = &global_state;
+            let panic::AssertUnwindSafe(global_state) = global_state;
             let _pctx = stdx::panic_context::enter(format!(
                 "\nversion: {}\nrequest: {} {:#?}",
                 env!("REV"),
                 R::METHOD,
                 params
             ));
-            let result = f(world.0, params);
+            let result = f(global_state, params);
             result_to_response::<R>(id, result)
         })
         .map_err(|_err| format!("sync task {:?} panicked", R::METHOD))?;
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index 1330370472..42eff1875e 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -420,12 +420,12 @@ impl GlobalState {
                 self.prime_caches_queue.request_op();
                 if self.prime_caches_queue.should_start_op() {
                     self.task_pool.handle.spawn_with_sender({
-                        let snap = self.snapshot();
+                        let analysis = self.snapshot().analysis;
                         move |sender| {
                             let cb = |progress| {
                                 sender.send(Task::PrimeCaches(progress)).unwrap();
                             };
-                            match snap.analysis.prime_caches(cb) {
+                            match analysis.prime_caches(cb) {
                                 Ok(()) => (),
                                 Err(_canceled) => (),
                             }