diff --git a/compiler/rustc_typeck/src/hir_wf_check.rs b/compiler/rustc_typeck/src/hir_wf_check.rs
index fa9c44bb89191..a8ec7b79e571f 100644
--- a/compiler/rustc_typeck/src/hir_wf_check.rs
+++ b/compiler/rustc_typeck/src/hir_wf_check.rs
@@ -121,7 +121,11 @@ fn diagnostic_hir_wf_check<'tcx>(
 
     let ty = match tcx.hir().get(hir_id) {
         hir::Node::ImplItem(item) => match item.kind {
-            hir::ImplItemKind::TyAlias(ref ty) => Some(ty),
+            hir::ImplItemKind::TyAlias(ty) => Some(ty),
+            _ => None,
+        },
+        hir::Node::TraitItem(item) => match item.kind {
+            hir::TraitItemKind::Type(_, ty) => ty,
             _ => None,
         },
         _ => None,
diff --git a/src/test/ui/associated-types/defaults-wf.stderr b/src/test/ui/associated-types/defaults-wf.stderr
index d4fa5be742ff3..73ef567ffae6d 100644
--- a/src/test/ui/associated-types/defaults-wf.stderr
+++ b/src/test/ui/associated-types/defaults-wf.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
-  --> $DIR/defaults-wf.rs:7:5
+  --> $DIR/defaults-wf.rs:7:15
    |
 LL |     type Ty = Vec<[u8]>;
-   |     ^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |               ^^^^^^^^^ doesn't have a size known at compile-time
    | 
   ::: $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
    |
diff --git a/src/test/ui/wf/wf-trait-associated-type-trait.rs b/src/test/ui/wf/wf-trait-associated-type-trait.rs
index ddc0b323a11a1..d67e110edeeee 100644
--- a/src/test/ui/wf/wf-trait-associated-type-trait.rs
+++ b/src/test/ui/wf/wf-trait-associated-type-trait.rs
@@ -8,7 +8,7 @@ struct IsCopy<T:Copy> { x: T }
 
 trait SomeTrait {
     type Type1;
-    type Type2 = IsCopy<Self::Type1>;
+    type Type2 = (IsCopy<Self::Type1>, bool);
     //~^ ERROR E0277
 }
 
diff --git a/src/test/ui/wf/wf-trait-associated-type-trait.stderr b/src/test/ui/wf/wf-trait-associated-type-trait.stderr
index a139186ebb673..d1c2c65043d21 100644
--- a/src/test/ui/wf/wf-trait-associated-type-trait.stderr
+++ b/src/test/ui/wf/wf-trait-associated-type-trait.stderr
@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `<Self as SomeTrait>::Type1: Copy` is not satisfied
-  --> $DIR/wf-trait-associated-type-trait.rs:11:5
+  --> $DIR/wf-trait-associated-type-trait.rs:11:19
    |
 LL | struct IsCopy<T:Copy> { x: T }
    |                 ---- required by this bound in `IsCopy`
 ...
-LL |     type Type2 = IsCopy<Self::Type1>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `<Self as SomeTrait>::Type1`
+LL |     type Type2 = (IsCopy<Self::Type1>, bool);
+   |                   ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `<Self as SomeTrait>::Type1`
    |
 help: consider further restricting the associated type
    |