2 files changed, 14 insertions, 1 deletions
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs
index aa42f8936f3..0fdb772c262 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs
@@ -258,6 +258,9 @@ where
                 if Q::in_adt_inherently(cx, def, substs) {
                     return true;
                 }
+                if def.is_union() && Q::in_any_value_of_ty(cx, rvalue.ty(cx.body, cx.tcx)) {
+                    return true;
+                }
             }
 
             // Otherwise, proceed structurally...
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs
index e20b86dd452..f516c07243e 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs
@@ -42,9 +42,19 @@ where
         }
     }
 
-    fn assign_qualif_direct(&mut self, place: &mir::Place<'tcx>, value: bool) {
+    fn assign_qualif_direct(&mut self, place: &mir::Place<'tcx>, mut value: bool) {
         debug_assert!(!place.is_indirect());
 
+        if !value {
+            for (base, _elem) in place.iter_projections() {
+                let base_ty = base.ty(self.ccx.body, self.ccx.tcx);
+                if base_ty.ty.is_union() && Q::in_any_value_of_ty(self.ccx, base_ty.ty) {
+                    value = true;
+                    break;
+                }
+            }
+        }
+
         match (value, place.as_ref()) {
             (true, mir::PlaceRef { local, .. }) => {
                 self.qualifs_per_local.insert(local);