diff --git a/compiler/rustc_hir/src/hir_id.rs b/compiler/rustc_hir/src/hir_id.rs
index 1482a96cae3..5b486819c35 100644
--- a/compiler/rustc_hir/src/hir_id.rs
+++ b/compiler/rustc_hir/src/hir_id.rs
@@ -19,11 +19,13 @@ pub struct HirId {
 }
 
 impl HirId {
+    #[inline]
     pub fn expect_owner(self) -> LocalDefId {
         assert_eq!(self.local_id.index(), 0);
         self.owner
     }
 
+    #[inline]
     pub fn as_owner(self) -> Option<LocalDefId> {
         if self.local_id.index() == 0 { Some(self.owner) } else { None }
     }