diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index ecc7b170818d2..b1c8f750d65d4 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -267,7 +267,7 @@ fn visit_implementation_of_coerce_shared(checker: &Checker<'_>) -> Result<(), Er
     // Just compute this for the side-effects, in particular reporting
     // errors; other parts of the code may demand it for the info of
     // course.
-    coerce_shared_info(tcx, impl_did)
+    tcx.ensure_result().coerce_shared_info(impl_did)
 }
 
 fn is_from_coerce_pointee_derive(tcx: TyCtxt<'_>, span: Span) -> bool {
diff --git a/compiler/rustc_hir_analysis/src/coherence/mod.rs b/compiler/rustc_hir_analysis/src/coherence/mod.rs
index 8391a47902e42..d23f1ddaa790d 100644
--- a/compiler/rustc_hir_analysis/src/coherence/mod.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/mod.rs
@@ -140,7 +140,7 @@ fn enforce_empty_impls_for_marker_traits(
 
 /// Adds query implementations to the [Providers] vtable, see [`rustc_middle::query`].
 pub(crate) fn provide(providers: &mut Providers) {
-    use self::builtin::coerce_unsized_info;
+    use self::builtin::{coerce_shared_info, coerce_unsized_info};
     use self::inherent_impls::{
         crate_incoherent_impls, crate_inherent_impls, crate_inherent_impls_validity_check,
         inherent_impls,
@@ -155,6 +155,7 @@ pub(crate) fn provide(providers: &mut Providers) {
         inherent_impls,
         crate_inherent_impls_validity_check,
         crate_inherent_impls_overlap_check,
+        coerce_shared_info,
         coerce_unsized_info,
         orphan_check_impl,
         ..*providers
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 986e127ac6b8b..ca4348fd51fa0 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -997,10 +997,22 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             self.tcx,
             ObligationCause::dummy(),
             self.param_env,
-            ty::Binder::dummy(coerce_shared_trait_ref),
+            coerce_shared_trait_ref,
         );
+
+        let mut selcx = traits::SelectionContext::new(self);
+        let Ok(Some(impl_source)) = selcx.select(&obligation) else {
+            return Err(TypeError::Mismatch);
+        };
+        if let ImplSource::UserDefined(impl_source) = &impl_source
+            && let Some(impl_def_id) = impl_source.impl_def_id.as_local()
+            && let Err(guar) = self.tcx.ensure_result().coerce_shared_info(impl_def_id)
+        {
+            self.fcx.set_tainted_by_errors(guar);
+        }
+
         let ocx = ObligationCtxt::new(&self.infcx);
-        ocx.register_obligation(obligation);
+        ocx.register_obligations(impl_source.nested_obligations());
         let errs = ocx.evaluate_obligations_error_on_ambiguity();
         if errs.is_empty() {
             Ok(InferOk {
diff --git a/compiler/rustc_middle/src/queries.rs b/compiler/rustc_middle/src/queries.rs
index cbd54ec959c6a..241c3296710e0 100644
--- a/compiler/rustc_middle/src/queries.rs
+++ b/compiler/rustc_middle/src/queries.rs
@@ -1205,6 +1205,10 @@ rustc_queries! {
         separate_provide_extern
     }
 
+    query coerce_shared_info(key: LocalDefId) -> Result<(), ErrorGuaranteed> {
+        desc { "computing CoerceShared info for `{}`", tcx.def_path_str(key) }
+    }
+
     query typeck_root(key: LocalDefId) -> &'tcx ty::TypeckResults<'tcx> {
         desc { "type-checking `{}`", tcx.def_path_str(key) }
         cache_on_disk
diff --git a/tests/crashes/reborrow/coerce-shared-alias-projection.rs b/tests/ui/reborrow/coerce-shared-alias-projection.rs
similarity index 89%
rename from tests/crashes/reborrow/coerce-shared-alias-projection.rs
rename to tests/ui/reborrow/coerce-shared-alias-projection.rs
index 8497455de921a..d7185c6dc7324 100644
--- a/tests/crashes/reborrow/coerce-shared-alias-projection.rs
+++ b/tests/ui/reborrow/coerce-shared-alias-projection.rs
@@ -1,4 +1,5 @@
-//@ known-bug: unknown
+// Alias and projection fields in invalid multi-field `CoerceShared` impls must not cause an ICE.
+
 #![feature(reborrow)]
 #![allow(dead_code)]
 
@@ -62,6 +63,7 @@ impl<'a, T> Clone for OuterAliasRef<'a, T> {
 impl<'a, T> Copy for OuterAliasRef<'a, T> {}
 
 impl<'a, T> CoerceShared<OuterAliasRef<'a, T>> for OuterMut<'a, T> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 struct OuterProjectionRef<'a, T: 'a> {
     inner: ProjectedInnerRef<'a, T>,
@@ -77,6 +79,7 @@ impl<'a, T: 'a> Clone for OuterProjectionRef<'a, T> {
 impl<'a, T: 'a> Copy for OuterProjectionRef<'a, T> {}
 
 impl<'a, T: 'a> CoerceShared<OuterProjectionRef<'a, T>> for OuterMut<'a, T> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 fn read_alias<'a>(outer: OuterAliasRef<'a, u32>) -> (&'a u32, usize) {
     (outer.inner.value, outer.tag)
diff --git a/tests/ui/reborrow/coerce-shared-alias-projection.stderr b/tests/ui/reborrow/coerce-shared-alias-projection.stderr
new file mode 100644
index 0000000000000..ec2ef16c1ef97
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-alias-projection.stderr
@@ -0,0 +1,14 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-alias-projection.rs:65:13
+   |
+LL | impl<'a, T> CoerceShared<OuterAliasRef<'a, T>> for OuterMut<'a, T> {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-alias-projection.rs:81:17
+   |
+LL | impl<'a, T: 'a> CoerceShared<OuterProjectionRef<'a, T>> for OuterMut<'a, T> {}
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/crashes/reborrow/coerce-shared-different-layout.rs b/tests/ui/reborrow/coerce-shared-different-layout.rs
similarity index 81%
rename from tests/crashes/reborrow/coerce-shared-different-layout.rs
rename to tests/ui/reborrow/coerce-shared-different-layout.rs
index ad285bf0130d1..db47167f126ae 100644
--- a/tests/crashes/reborrow/coerce-shared-different-layout.rs
+++ b/tests/ui/reborrow/coerce-shared-different-layout.rs
@@ -1,4 +1,5 @@
-//@ known-bug: unknown
+// `CoerceShared` impls with incompatible data-field layouts must be rejected without an ICE.
+
 #![feature(reborrow)]
 #![allow(dead_code)]
 
@@ -27,6 +28,7 @@ impl<'a, T> Clone for ImbrisRef<'a, T> {
 impl<'a, T> Copy for ImbrisRef<'a, T> {}
 
 impl<'a, T> CoerceShared<ImbrisRef<'a, T>> for ImbrisMut<'a, T> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 fn ptr(value: ImbrisRef<'_, i32>) -> NonNull<i32> {
     value.ptr
diff --git a/tests/ui/reborrow/coerce-shared-different-layout.stderr b/tests/ui/reborrow/coerce-shared-different-layout.stderr
new file mode 100644
index 0000000000000..b5d6d8b83794e
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-different-layout.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-different-layout.rs:30:13
+   |
+LL | impl<'a, T> CoerceShared<ImbrisRef<'a, T>> for ImbrisMut<'a, T> {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.current.stderr b/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.current.stderr
new file mode 100644
index 0000000000000..f477a473e7d2c
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.current.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-invalid-consteval-issue-158149.rs:19:10
+   |
+LL | impl<'a> CoerceShared<MyRef<'a>> for MyMut<'a> {}
+   |          ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.next.stderr b/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.next.stderr
new file mode 100644
index 0000000000000..f477a473e7d2c
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.next.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-invalid-consteval-issue-158149.rs:19:10
+   |
+LL | impl<'a> CoerceShared<MyRef<'a>> for MyMut<'a> {}
+   |          ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.rs b/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.rs
new file mode 100644
index 0000000000000..8368a2028f7ce
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-invalid-consteval-issue-158149.rs
@@ -0,0 +1,29 @@
+//@ revisions: current next
+//@[next] compile-flags: -Znext-solver
+
+// Invalid `CoerceShared` impls must taint type checking before CTFE.
+
+#![feature(const_block_items)]
+#![feature(reborrow)]
+#![allow(dead_code, unused_variables)]
+
+use std::marker::CoerceShared;
+
+struct MyMut<'a>(&'a u8);
+#[derive(Copy, Clone)]
+struct MyRef<'a> {
+    x: &'a (),
+    y: &'a (),
+}
+
+impl<'a> CoerceShared<MyRef<'a>> for MyMut<'a> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+
+const {
+    let value = 1;
+    consume(MyMut(&value));
+}
+
+const fn consume(_: MyRef<'_>) {}
+
+fn main() {}
diff --git a/tests/crashes/reborrow/coerce-shared-marker-no-target-lifetime.rs b/tests/ui/reborrow/coerce-shared-marker-no-target-lifetime.rs
similarity index 66%
rename from tests/crashes/reborrow/coerce-shared-marker-no-target-lifetime.rs
rename to tests/ui/reborrow/coerce-shared-marker-no-target-lifetime.rs
index 3cdbf515371f2..f5ef3827470ca 100644
--- a/tests/crashes/reborrow/coerce-shared-marker-no-target-lifetime.rs
+++ b/tests/ui/reborrow/coerce-shared-marker-no-target-lifetime.rs
@@ -1,6 +1,7 @@
-//@ known-bug: unknown
 //@ edition: 2024
 
+// A `CoerceShared` target without a reborrowed lifetime must be rejected without an ICE.
+
 #![feature(reborrow)]
 
 use std::marker::{CoerceShared, PhantomData, Reborrow};
@@ -10,12 +11,11 @@ struct CustomMarkerRef;
 
 impl<'a> Reborrow for CustomMarker<'a> {}
 impl<'a> CoerceShared<CustomMarkerRef> for CustomMarker<'a> {}
-//~^ ERROR
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 fn method(_a: CustomMarkerRef) {}
 
 fn main() {
     let a = CustomMarker(PhantomData);
     method(a);
-    //~^ ERROR
 }
diff --git a/tests/ui/reborrow/coerce-shared-marker-no-target-lifetime.stderr b/tests/ui/reborrow/coerce-shared-marker-no-target-lifetime.stderr
new file mode 100644
index 0000000000000..bc0addd2f1cd6
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-marker-no-target-lifetime.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-marker-no-target-lifetime.rs:13:10
+   |
+LL | impl<'a> CoerceShared<CustomMarkerRef> for CustomMarker<'a> {}
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/crashes/reborrow/coerce-shared-multi-field.rs b/tests/ui/reborrow/coerce-shared-multi-field.rs
similarity index 86%
rename from tests/crashes/reborrow/coerce-shared-multi-field.rs
rename to tests/ui/reborrow/coerce-shared-multi-field.rs
index 3bf5b64064d4a..519c5306a848c 100644
--- a/tests/crashes/reborrow/coerce-shared-multi-field.rs
+++ b/tests/ui/reborrow/coerce-shared-multi-field.rs
@@ -1,4 +1,5 @@
-//@ known-bug: unknown
+// Multi-field `CoerceShared` impls must be rejected without reaching malformed reborrow MIR.
+
 #![feature(reborrow)]
 #![allow(dead_code)]
 
@@ -34,6 +35,7 @@ impl<'a, T> Clone for MatRef<'a, T> {
 impl<'a, T> Copy for MatRef<'a, T> {}
 
 impl<'a, T> CoerceShared<MatRef<'a, T>> for MatMut<'a, T> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 fn dims<T>(mat: MatRef<'_, T>) -> (usize, usize, usize, usize) {
     let _ = mat.ptr;
diff --git a/tests/ui/reborrow/coerce-shared-multi-field.stderr b/tests/ui/reborrow/coerce-shared-multi-field.stderr
new file mode 100644
index 0000000000000..61c2a8f4c6a0e
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-multi-field.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-multi-field.rs:37:13
+   |
+LL | impl<'a, T> CoerceShared<MatRef<'a, T>> for MatMut<'a, T> {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/crashes/reborrow/coerce-shared-nested.rs b/tests/ui/reborrow/coerce-shared-nested.rs
similarity index 86%
rename from tests/crashes/reborrow/coerce-shared-nested.rs
rename to tests/ui/reborrow/coerce-shared-nested.rs
index a916dde881ec5..c3f40be89fdad 100644
--- a/tests/crashes/reborrow/coerce-shared-nested.rs
+++ b/tests/ui/reborrow/coerce-shared-nested.rs
@@ -1,4 +1,5 @@
-//@ known-bug: unknown
+// Invalid nested multi-field `CoerceShared` impls must be rejected without an ICE.
+
 #![feature(reborrow)]
 #![allow(dead_code)]
 
@@ -45,6 +46,7 @@ impl<'a, T> Clone for OuterRef<'a, T> {
 impl<'a, T> Copy for OuterRef<'a, T> {}
 
 impl<'a, T> CoerceShared<OuterRef<'a, T>> for OuterMut<'a, T> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 fn get<'a>(outer: OuterRef<'a, i32>) -> (&'a i32, usize) {
     (outer.inner.value, outer.tag)
diff --git a/tests/ui/reborrow/coerce-shared-nested.stderr b/tests/ui/reborrow/coerce-shared-nested.stderr
new file mode 100644
index 0000000000000..1a435bb3c9bda
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-nested.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-nested.rs:48:13
+   |
+LL | impl<'a, T> CoerceShared<OuterRef<'a, T>> for OuterMut<'a, T> {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.rs b/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.rs
index ade1890068d76..fb4eb86781a0e 100644
--- a/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.rs
+++ b/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.rs
@@ -47,7 +47,6 @@ fn main() {
     let shared = get(wrapped);
 
     *wrapped.extra.value = 3;
-    //~^ ERROR cannot assign to `*wrapped.extra.value` because it is borrowed
 
     let _ = shared;
 }
diff --git a/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.stderr b/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.stderr
index d718103c80e7f..3610bcea23b64 100644
--- a/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.stderr
+++ b/tests/ui/reborrow/coerce-shared-omitted-reborrow-field-locked.stderr
@@ -4,18 +4,5 @@ error: implementing `CoerceShared` does not allow multiple lifetimes or fields t
 LL | impl<'a, T> CoerceShared<OmitRef<'a, T>> for OmitMut<'a, T> {}
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0506]: cannot assign to `*wrapped.extra.value` because it is borrowed
-  --> $DIR/coerce-shared-omitted-reborrow-field-locked.rs:49:5
-   |
-LL |     let shared = get(wrapped);
-   |                      ------- `*wrapped.extra.value` is borrowed here
-LL |
-LL |     *wrapped.extra.value = 3;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^
-   |     |
-   |     `*wrapped.extra.value` is assigned to here but it was already borrowed
-   |     borrow later used here
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0506`.
diff --git a/tests/crashes/reborrow/coerce-shared-tuple-phantom-position.rs b/tests/ui/reborrow/coerce-shared-tuple-phantom-position.rs
similarity index 91%
rename from tests/crashes/reborrow/coerce-shared-tuple-phantom-position.rs
rename to tests/ui/reborrow/coerce-shared-tuple-phantom-position.rs
index 0ada68c9c20f7..5be596ccd6bd9 100644
--- a/tests/crashes/reborrow/coerce-shared-tuple-phantom-position.rs
+++ b/tests/ui/reborrow/coerce-shared-tuple-phantom-position.rs
@@ -1,4 +1,5 @@
-//@ known-bug: unknown
+// `PhantomData` positions must not hide invalid multi-field `CoerceShared` impls or cause an ICE.
+
 #![feature(reborrow)]
 #![allow(dead_code)]
 
@@ -56,6 +57,7 @@ impl<'a, T, U> Clone for InterleavedRef<'a, T, U> {
 impl<'a, T, U> Copy for InterleavedRef<'a, T, U> {}
 
 impl<'a, T, U> CoerceShared<InterleavedRef<'a, T, U>> for InterleavedMut<'a, T, U> {}
+//~^ ERROR implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
 
 fn read_source_leading<'a>(value: SourceLeadingRef<'a, i32>) -> &'a i32 {
     value.0
diff --git a/tests/ui/reborrow/coerce-shared-tuple-phantom-position.stderr b/tests/ui/reborrow/coerce-shared-tuple-phantom-position.stderr
new file mode 100644
index 0000000000000..3e4a4e52e473b
--- /dev/null
+++ b/tests/ui/reborrow/coerce-shared-tuple-phantom-position.stderr
@@ -0,0 +1,8 @@
+error: implementing `CoerceShared` does not allow multiple lifetimes or fields to be coerced
+  --> $DIR/coerce-shared-tuple-phantom-position.rs:59:16
+   |
+LL | impl<'a, T, U> CoerceShared<InterleavedRef<'a, T, U>> for InterleavedMut<'a, T, U> {}
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/crashes/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.rs b/tests/ui/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.rs
similarity index 66%
rename from tests/crashes/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.rs
rename to tests/ui/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.rs
index 59e76ec36ab90..153bb12d5a2ba 100644
--- a/tests/crashes/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.rs
+++ b/tests/ui/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.rs
@@ -1,4 +1,4 @@
-//@ known-bug: unknown
+// An invalid `CoerceShared` field relation must report an error instead of causing an ICE.
 
 #![feature(reborrow)]
 
@@ -9,9 +9,9 @@ struct CustomMut<'a, T>(&'a mut T);
 impl<'a, T> Reborrow for CustomMut<'a, T> {}
 
 struct CustomRef<'a, T>(&'a CustomMut<'a, T>);
-//~^ ERROR
 
 impl<'a, T> CoerceShared<CustomRef<'a, T>> for CustomMut<'a, T> {}
+//~^ ERROR the trait bound `&'a mut T: CoerceShared<&'a CustomMut<'a, T>>` is not satisfied
 
 fn method(_a: CustomRef<'_, ()>) {}
 
diff --git a/tests/ui/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.stderr b/tests/ui/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.stderr
new file mode 100644
index 0000000000000..7eb8d9905cc2b
--- /dev/null
+++ b/tests/ui/reborrow/corrected-field-mismatch-coerce-shared-issue-156315.stderr
@@ -0,0 +1,9 @@
+error[E0277]: the trait bound `&'a mut T: CoerceShared<&'a CustomMut<'a, T>>` is not satisfied
+  --> $DIR/corrected-field-mismatch-coerce-shared-issue-156315.rs:13:1
+   |
+LL | impl<'a, T> CoerceShared<CustomRef<'a, T>> for CustomMut<'a, T> {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the nightly-only, unstable trait `CoerceShared<&'a CustomMut<'a, T>>` is not implemented for `&'a mut T`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/crashes/reborrow/missing-generic-args-coerce-shared-issue-156315.rs b/tests/ui/reborrow/missing-generic-args-coerce-shared-issue-156315.rs
similarity index 86%
rename from tests/crashes/reborrow/missing-generic-args-coerce-shared-issue-156315.rs
rename to tests/ui/reborrow/missing-generic-args-coerce-shared-issue-156315.rs
index d365986901fe3..18a0cb5eb05cb 100644
--- a/tests/crashes/reborrow/missing-generic-args-coerce-shared-issue-156315.rs
+++ b/tests/ui/reborrow/missing-generic-args-coerce-shared-issue-156315.rs
@@ -1,4 +1,5 @@
-//@ known-bug: unknown
+// Missing generic arguments in a `CoerceShared` field must not cause an additional ICE.
+
 #![feature(reborrow)]
 
 // Malformed no-ICE regression: this intentionally keeps the missing generic arguments from the
@@ -14,7 +15,6 @@ impl<'a, T> CoerceShared<CustomRef<'a, T>> for CustomMut<'a, T> {}
 struct CustomRef<'a, T>(&'a CustomMut);
 //~^ ERROR
 //~| ERROR
-//~| ERROR
 
 fn method(_a: CustomRef<'_, ()>) {}
 
diff --git a/tests/ui/reborrow/missing-generic-args-coerce-shared-issue-156315.stderr b/tests/ui/reborrow/missing-generic-args-coerce-shared-issue-156315.stderr
new file mode 100644
index 0000000000000..01adc64ab2520
--- /dev/null
+++ b/tests/ui/reborrow/missing-generic-args-coerce-shared-issue-156315.stderr
@@ -0,0 +1,31 @@
+error[E0106]: missing lifetime specifier
+  --> $DIR/missing-generic-args-coerce-shared-issue-156315.rs:15:29
+   |
+LL | struct CustomRef<'a, T>(&'a CustomMut);
+   |                             ^^^^^^^^^ expected named lifetime parameter
+   |
+help: consider using the `'a` lifetime
+   |
+LL | struct CustomRef<'a, T>(&'a CustomMut<'a>);
+   |                                      ++++
+
+error[E0107]: missing generics for struct `CustomMut`
+  --> $DIR/missing-generic-args-coerce-shared-issue-156315.rs:15:29
+   |
+LL | struct CustomRef<'a, T>(&'a CustomMut);
+   |                             ^^^^^^^^^ expected 1 generic argument
+   |
+note: struct defined here, with 1 generic parameter: `T`
+  --> $DIR/missing-generic-args-coerce-shared-issue-156315.rs:10:8
+   |
+LL | struct CustomMut<'a, T>(&'a mut T);
+   |        ^^^^^^^^^     -
+help: add missing generic argument
+   |
+LL | struct CustomRef<'a, T>(&'a CustomMut<T>);
+   |                                      +++
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0106, E0107.
+For more information about an error, try `rustc --explain E0106`.