diff --git a/compiler/rustc_middle/src/ty/fast_reject.rs b/compiler/rustc_middle/src/ty/fast_reject.rs
index a4fb51303c580..86158fec021f9 100644
--- a/compiler/rustc_middle/src/ty/fast_reject.rs
+++ b/compiler/rustc_middle/src/ty/fast_reject.rs
@@ -167,6 +167,7 @@ pub struct DeepRejectCtxt {
 }
 
 impl DeepRejectCtxt {
+    #[inline]
     pub fn args_may_unify<'tcx>(
         self,
         obligation_args: GenericArgsRef<'tcx>,
@@ -329,6 +330,7 @@ impl DeepRejectCtxt {
         }
     }
 
+    #[inline(always)]
     pub fn consts_may_unify(self, obligation_ct: ty::Const<'_>, impl_ct: ty::Const<'_>) -> bool {
         let k = impl_ct.kind();
         let impl_val = match k {