diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs
index 06366b6fc31d5..bc72e9d94a953 100644
--- a/compiler/rustc_mir_transform/src/generator.rs
+++ b/compiler/rustc_mir_transform/src/generator.rs
@@ -342,7 +342,7 @@ impl MutVisitor<'tcx> for TransformVisitor<'tcx> {
             let source_info = data.terminator().source_info;
             // We must assign the value first in case it gets declared dead below
             data.statements.extend(self.make_state(state_idx, v, source_info));
-            let state = if let Some((resume, resume_arg)) = resume {
+            let state = if let Some((resume, mut resume_arg)) = resume {
                 // Yield
                 let state = 3 + self.suspension_points.len();
 
@@ -350,7 +350,8 @@ impl MutVisitor<'tcx> for TransformVisitor<'tcx> {
                 // live across a yield.
                 let resume_arg =
                     if let Some(&(ty, variant, idx)) = self.remap.get(&resume_arg.local) {
-                        self.make_field(variant, idx, ty)
+                        replace_base(&mut resume_arg, self.make_field(variant, idx, ty), self.tcx);
+                        resume_arg
                     } else {
                         resume_arg
                     };
diff --git a/src/test/ui/generator/yield-in-box.rs b/src/test/ui/generator/yield-in-box.rs
index 65f368df9cb33..dd6fa7c151aa7 100644
--- a/src/test/ui/generator/yield-in-box.rs
+++ b/src/test/ui/generator/yield-in-box.rs
@@ -1,8 +1,10 @@
 // run-pass
-
 // Test that box-statements with yields in them work.
 
-#![feature(generators, box_syntax)]
+#![feature(generators, box_syntax, generator_trait)]
+use std::pin::Pin;
+use std::ops::Generator;
+use std::ops::GeneratorState;
 
 fn main() {
     let x = 0i32;
@@ -15,4 +17,8 @@ fn main() {
             _t => {}
         }
     };
+
+    let mut g = |_| box yield;
+    assert_eq!(Pin::new(&mut g).resume(1), GeneratorState::Yielded(()));
+    assert_eq!(Pin::new(&mut g).resume(2), GeneratorState::Complete(box 2));
 }
diff --git a/src/test/ui/generator/yield-in-box.stderr b/src/test/ui/generator/yield-in-box.stderr
index 24de18edb0f8c..7602e803945dc 100644
--- a/src/test/ui/generator/yield-in-box.stderr
+++ b/src/test/ui/generator/yield-in-box.stderr
@@ -1,5 +1,5 @@
 warning: unused generator that must be used
-  --> $DIR/yield-in-box.rs:9:5
+  --> $DIR/yield-in-box.rs:11:5
    |
 LL | /     || {
 LL | |         let y = 2u32;