3 files changed, 43 insertions, 12 deletions
diff --git a/src/tools/rust-analyzer/Cargo.lock b/src/tools/rust-analyzer/Cargo.lock
index c5a211dc4d7..3a7ebb9da44 100644
--- a/src/tools/rust-analyzer/Cargo.lock
+++ b/src/tools/rust-analyzer/Cargo.lock
@@ -194,9 +194,9 @@ checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
 
 [[package]]
 name = "chalk-derive"
-version = "0.98.0"
+version = "0.99.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9426c8fd0fe61c3da880b801d3b510524df17843a8f9ec1f5b9cec24fb7412df"
+checksum = "572583d9b97f9d277e5c7607f8239a30e2e04d3ed3b47c87d1cb2152ae724073"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -206,9 +206,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-ir"
-version = "0.98.0"
+version = "0.99.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d5f2eb1cd6054da221bd1ac0197fb2fe5e2caf3dcb93619398fc1433f8f09093"
+checksum = "e60e0ef9c81dce1336a9ed3c76f08775f5b623151d96d85ba45f7b10de76d1c7"
 dependencies = [
  "bitflags 2.7.0",
  "chalk-derive",
@@ -216,9 +216,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-recursive"
-version = "0.98.0"
+version = "0.99.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "129dc03458f71cfb9c3cd621c9c68166a94e87b85b16ccd29af015d7ff9a1c61"
+checksum = "5a06350d614e22b03a69b8105e3541614450a7ea48bc58ecc6c6bd92731a3995"
 dependencies = [
  "chalk-derive",
  "chalk-ir",
@@ -229,9 +229,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-solve"
-version = "0.98.0"
+version = "0.99.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d7e8a8c1e928f98cdf227b868416ef21dcd8cc3c61b347576d783713444d41c8"
+checksum = "0e428761e9b55bee516bfe2457caed8b6d1b86353f92ae825bbe438a36ce91e8"
 dependencies = [
  "chalk-derive",
  "chalk-ir",
diff --git a/src/tools/rust-analyzer/Cargo.toml b/src/tools/rust-analyzer/Cargo.toml
index 629bd744676..ab00d017395 100644
--- a/src/tools/rust-analyzer/Cargo.toml
+++ b/src/tools/rust-analyzer/Cargo.toml
@@ -106,10 +106,10 @@ arrayvec = "0.7.4"
 bitflags = "2.4.1"
 cargo_metadata = "0.18.1"
 camino = "1.1.6"
-chalk-solve = { version = "0.98.0", default-features = false }
-chalk-ir = "0.98.0"
-chalk-recursive = { version = "0.98.0", default-features = false }
-chalk-derive = "0.98.0"
+chalk-solve = { version = "0.99.0", default-features = false }
+chalk-ir = "0.99.0"
+chalk-recursive = { version = "0.99.0", default-features = false }
+chalk-derive = "0.99.0"
 crossbeam-channel = "0.5.8"
 dissimilar = "1.0.7"
 dot = "0.1.4"
diff --git a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/type_mismatch.rs b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/type_mismatch.rs
index bfdda537405..56afb38cc81 100644
--- a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/type_mismatch.rs
+++ b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/type_mismatch.rs
@@ -1164,6 +1164,37 @@ struct Bar {
     }
 
     #[test]
+    fn trait_upcast_ok() {
+        check_diagnostics(
+            r#"
+//- minicore: coerce_unsized
+trait A: B {}
+trait B {}
+
+fn test(a: &dyn A) -> &dyn B {
+    a
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn trait_upcast_err() {
+        check_diagnostics(
+            r#"
+//- minicore: coerce_unsized
+trait A {} // `A` does not have `B` as a supertrait, so no upcast :c
+trait B {}
+
+fn test(a: &dyn A) -> &dyn B {
+    a
+  //^ error: expected &dyn B, found &dyn A
+}
+"#,
+        );
+    }
+
+    #[test]
     fn return_no_value() {
         check_diagnostics_with_disabled(
             r#"