diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 9906be60e3e95..a98e6943d68ee 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -612,7 +612,9 @@ fn write_mir_sig(tcx: TyCtxt<'_>, body: &Body<'_>, w: &mut dyn io::Write) -> io:
     let def_id = body.source.def_id();
     let kind = tcx.def_kind(def_id);
     let is_function = match kind {
-        DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(..) => true,
+        DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(..) | DefKind::SyntheticCoroutineBody => {
+            true
+        }
         _ => tcx.is_closure_like(def_id),
     };
     match (kind, body.source.promoted) {
diff --git a/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs b/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs
index ebe8d2eff4ff3..cf39c136b01a3 100644
--- a/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs
+++ b/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs
@@ -207,11 +207,12 @@ pub fn coroutine_by_move_body_def_id<'tcx>(
 
     let mut by_move_body = body.clone();
     MakeByMoveBody { tcx, field_remapping, by_move_coroutine_ty }.visit_body(&mut by_move_body);
-    dump_mir(tcx, false, "coroutine_by_move", &0, &by_move_body, |_, _| Ok(()));
 
-    let body_def = tcx.create_def(coroutine_def_id, kw::Empty, DefKind::SyntheticCoroutineBody);
+    // This will always be `{closure#1}`, since the original coroutine is `{closure#0}`.
+    let body_def = tcx.create_def(parent_def_id, kw::Empty, DefKind::SyntheticCoroutineBody);
     by_move_body.source =
         mir::MirSource::from_instance(InstanceKind::Item(body_def.def_id().to_def_id()));
+    dump_mir(tcx, false, "built", &"after", &by_move_body, |_, _| Ok(()));
 
     // Inherited from the by-ref coroutine.
     body_def.codegen_fn_attrs(tcx.codegen_fn_attrs(coroutine_def_id).clone());
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.panic-abort.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.built.after.panic-unwind.mir
similarity index 81%
rename from tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.panic-abort.mir
rename to tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.built.after.panic-unwind.mir
index 1f5bb551b8e01..d273512b91fdb 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.panic-abort.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.built.after.panic-unwind.mir
@@ -1,11 +1,11 @@
-// MIR for `main::{closure#0}::{closure#0}::{closure#0}` 0 coroutine_by_move
+// MIR for `main::{closure#0}::{closure#0}::{closure#0}` after built
 
-fn main::{closure#0}::{closure#0}::{closure#0}(_1: {async closure body@$DIR/async_closure_shims.rs:53:53: 56:10}, _2: ResumeTy) -> ()
+fn main::{closure#0}::{closure#0}::{closure#0}(_1: {async closure body@$DIR/async_closure_shims.rs:55:53: 58:10}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
     debug a => (_1.0: i32);
-    debug b => (_1.1: i32);
+    debug b => (*(_1.1: &i32));
     let mut _0: ();
     let _3: i32;
     scope 1 {
@@ -28,7 +28,7 @@ yields ()
         _4 = &_3;
         FakeRead(ForLet(None), _4);
         StorageLive(_5);
-        _5 = &(_1.1: i32);
+        _5 = &(*(_1.1: &i32));
         FakeRead(ForLet(None), _5);
         _0 = const ();
         StorageDead(_5);
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.panic-unwind.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.panic-unwind.mir
similarity index 80%
rename from tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.panic-unwind.mir
rename to tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.panic-unwind.mir
index 1f5bb551b8e01..43f33219c7b42 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.panic-unwind.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.panic-unwind.mir
@@ -1,6 +1,6 @@
-// MIR for `main::{closure#0}::{closure#0}::{closure#0}` 0 coroutine_by_move
+// MIR for `main::{closure#0}::{closure#0}::{closure#1}` after built
 
-fn main::{closure#0}::{closure#0}::{closure#0}(_1: {async closure body@$DIR/async_closure_shims.rs:53:53: 56:10}, _2: ResumeTy) -> ()
+fn main::{closure#0}::{closure#0}::{closure#1}(_1: {async closure body@$DIR/async_closure_shims.rs:55:53: 58:10}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.panic-unwind.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.panic-unwind.mir
index a984845fd2c11..ce1d06ce1d3e9 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.panic-unwind.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.panic-unwind.mir
@@ -1,10 +1,10 @@
 // MIR for `main::{closure#0}::{closure#0}` 0 coroutine_closure_by_move
 
-fn main::{closure#0}::{closure#0}(_1: {async closure@$DIR/async_closure_shims.rs:53:33: 53:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:53:53: 56:10} {
-    let mut _0: {async closure body@$DIR/async_closure_shims.rs:53:53: 56:10};
+fn main::{closure#0}::{closure#0}(_1: {async closure@$DIR/async_closure_shims.rs:55:33: 55:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:55:53: 58:10} {
+    let mut _0: {async closure body@$DIR/async_closure_shims.rs:55:53: 58:10};
 
     bb0: {
-        _0 = {coroutine@$DIR/async_closure_shims.rs:53:53: 56:10 (#0)} { a: move _2, b: move (_1.0: i32) };
+        _0 = {coroutine@$DIR/async_closure_shims.rs:55:53: 58:10 (#0)} { a: move _2, b: move (_1.0: i32) };
         return;
     }
 }
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.panic-abort.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.built.after.panic-unwind.mir
similarity index 86%
rename from tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.panic-abort.mir
rename to tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.built.after.panic-unwind.mir
index 17fa93148064f..b4765c0b74ca8 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.panic-abort.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.built.after.panic-unwind.mir
@@ -1,6 +1,6 @@
-// MIR for `main::{closure#0}::{closure#1}::{closure#0}` 0 coroutine_by_move
+// MIR for `main::{closure#0}::{closure#1}::{closure#0}` after built
 
-fn main::{closure#0}::{closure#1}::{closure#0}(_1: {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10}, _2: ResumeTy) -> ()
+fn main::{closure#0}::{closure#1}::{closure#0}(_1: {async closure body@$DIR/async_closure_shims.rs:64:48: 67:10}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.panic-unwind.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.panic-unwind.mir
similarity index 80%
rename from tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.panic-unwind.mir
rename to tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.panic-unwind.mir
index 17fa93148064f..bf5be94b1aebf 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.panic-unwind.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.panic-unwind.mir
@@ -1,6 +1,6 @@
-// MIR for `main::{closure#0}::{closure#1}::{closure#0}` 0 coroutine_by_move
+// MIR for `main::{closure#0}::{closure#1}::{closure#1}` after built
 
-fn main::{closure#0}::{closure#1}::{closure#0}(_1: {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10}, _2: ResumeTy) -> ()
+fn main::{closure#0}::{closure#1}::{closure#1}(_1: {async closure body@$DIR/async_closure_shims.rs:64:48: 67:10}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_move.0.panic-unwind.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_move.0.panic-unwind.mir
index aab9f7b03b9ab..8452c79bf41bb 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_move.0.panic-unwind.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_move.0.panic-unwind.mir
@@ -1,10 +1,10 @@
 // MIR for `main::{closure#0}::{closure#1}` 0 coroutine_closure_by_move
 
-fn main::{closure#0}::{closure#1}(_1: {async closure@$DIR/async_closure_shims.rs:62:33: 62:47}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10} {
-    let mut _0: {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10};
+fn main::{closure#0}::{closure#1}(_1: {async closure@$DIR/async_closure_shims.rs:64:33: 64:47}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:64:48: 67:10} {
+    let mut _0: {async closure body@$DIR/async_closure_shims.rs:64:48: 67:10};
 
     bb0: {
-        _0 = {coroutine@$DIR/async_closure_shims.rs:62:48: 65:10 (#0)} { a: move _2, b: move (_1.0: &i32) };
+        _0 = {coroutine@$DIR/async_closure_shims.rs:64:48: 67:10 (#0)} { a: move _2, b: move (_1.0: &i32) };
         return;
     }
 }
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_ref.0.panic-unwind.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_ref.0.panic-unwind.mir
index 3fdc81791deef..08abe7197224c 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_ref.0.panic-unwind.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_ref.0.panic-unwind.mir
@@ -1,10 +1,10 @@
 // MIR for `main::{closure#0}::{closure#1}` 0 coroutine_closure_by_ref
 
-fn main::{closure#0}::{closure#1}(_1: &{async closure@$DIR/async_closure_shims.rs:62:33: 62:47}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10} {
-    let mut _0: {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10};
+fn main::{closure#0}::{closure#1}(_1: &{async closure@$DIR/async_closure_shims.rs:64:33: 64:47}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:64:48: 67:10} {
+    let mut _0: {async closure body@$DIR/async_closure_shims.rs:64:48: 67:10};
 
     bb0: {
-        _0 = {coroutine@$DIR/async_closure_shims.rs:62:48: 65:10 (#0)} { a: move _2, b: copy ((*_1).0: &i32) };
+        _0 = {coroutine@$DIR/async_closure_shims.rs:64:48: 67:10 (#0)} { a: move _2, b: copy ((*_1).0: &i32) };
         return;
     }
 }
diff --git a/tests/mir-opt/async_closure_shims.rs b/tests/mir-opt/async_closure_shims.rs
index 57c55ef055cd7..4d44025ac762a 100644
--- a/tests/mir-opt/async_closure_shims.rs
+++ b/tests/mir-opt/async_closure_shims.rs
@@ -22,7 +22,7 @@ pub fn block_on<T>(fut: impl Future<Output = T>) -> T {
     }
 }
 
-async fn call(f: &mut impl AsyncFn(i32)) {
+async fn call(f: &impl AsyncFn(i32)) {
     f(0).await;
 }
 
@@ -43,10 +43,12 @@ async fn call_normal_mut<F: Future<Output = ()>>(f: &mut impl FnMut(i32) -> F) {
 }
 
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.mir
-// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.mir
+// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.built.after.mir
+// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.mir
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_ref.0.mir
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_move.0.mir
-// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.coroutine_by_move.0.mir
+// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.built.after.mir
+// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.mir
 pub fn main() {
     block_on(async {
         let b = 2i32;
@@ -54,7 +56,7 @@ pub fn main() {
             let a = &a;
             let b = &b;
         };
-        call(&mut async_closure).await;
+        call(&async_closure).await;
         call_mut(&mut async_closure).await;
         call_once(async_closure).await;