diff --git a/tests/ui/associated-types/param-env-shadowing-false-positive.rs b/tests/ui/associated-types/param-env-shadowing-false-positive.rs
index e40d36dabc81..41993f5cba19 100644
--- a/tests/ui/associated-types/param-env-shadowing-false-positive.rs
+++ b/tests/ui/associated-types/param-env-shadowing-false-positive.rs
@@ -1,3 +1,7 @@
+// Regression test for issue #149910.
+// The compiler previously incorrectly claimed that the local param-env bound
+// shadowed the global impl, but they are actually the same.
+
 trait Trait {
     type Assoc;
 }
diff --git a/tests/ui/associated-types/param-env-shadowing-false-positive.stderr b/tests/ui/associated-types/param-env-shadowing-false-positive.stderr
index f4a687196ca1..64d7950f41ef 100644
--- a/tests/ui/associated-types/param-env-shadowing-false-positive.stderr
+++ b/tests/ui/associated-types/param-env-shadowing-false-positive.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/param-env-shadowing-false-positive.rs:10:5
+  --> $DIR/param-env-shadowing-false-positive.rs:14:5
    |
 LL | fn foo<T: Trait>(x: T::Assoc) -> u32 {
    |                                  --- expected `u32` because of return type
diff --git a/tests/ui/associated-types/param-env-shadowing-gat.rs b/tests/ui/associated-types/param-env-shadowing-gat.rs
index c7c559eb83b2..9dc91a1a1465 100644
--- a/tests/ui/associated-types/param-env-shadowing-gat.rs
+++ b/tests/ui/associated-types/param-env-shadowing-gat.rs
@@ -1,3 +1,7 @@
+// Regression test for issue #149910.
+// This ensures that the diagnostics logic handles Generic Associated Types (GATs)
+// correctly without crashing (ICE).
+
 trait Trait {
     type Assoc<T>;
 }
diff --git a/tests/ui/associated-types/param-env-shadowing-gat.stderr b/tests/ui/associated-types/param-env-shadowing-gat.stderr
index ed6e92c64ae0..02c024341724 100644
--- a/tests/ui/associated-types/param-env-shadowing-gat.stderr
+++ b/tests/ui/associated-types/param-env-shadowing-gat.stderr
@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/param-env-shadowing-gat.rs:10:5
+  --> $DIR/param-env-shadowing-gat.rs:14:5
    |
 LL | fn foo<T: Trait>(x: T::Assoc<T>) -> u32 {
    |                                     --- expected `u32` because of return type