diff --git a/compiler/rustc_type_ir/src/ir_print.rs b/compiler/rustc_type_ir/src/ir_print.rs
index c259a9747f0d4..388ad09cb200c 100644
--- a/compiler/rustc_type_ir/src/ir_print.rs
+++ b/compiler/rustc_type_ir/src/ir_print.rs
@@ -60,7 +60,7 @@ define_display_via_print!(
     PatternKind,
 );
 
-define_debug_via_print!(TraitRef, ExistentialTraitRef, ExistentialProjection, PatternKind);
+define_debug_via_print!(TraitRef, ExistentialTraitRef, PatternKind);
 
 impl<I: Interner, T> fmt::Display for OutlivesPredicate<I, T>
 where
diff --git a/compiler/rustc_type_ir/src/predicate.rs b/compiler/rustc_type_ir/src/predicate.rs
index 22d0fa23d0c56..8e10636ff657d 100644
--- a/compiler/rustc_type_ir/src/predicate.rs
+++ b/compiler/rustc_type_ir/src/predicate.rs
@@ -374,7 +374,7 @@ impl<I: Interner> ty::Binder<I, ExistentialTraitRef<I>> {
 }
 
 /// A `ProjectionPredicate` for an `ExistentialTraitRef`.
-#[derive_where(Clone, Copy, Hash, PartialEq, Eq; I: Interner)]
+#[derive_where(Clone, Copy, Hash, PartialEq, Eq, Debug; I: Interner)]
 #[derive(TypeVisitable_Generic, TypeFoldable_Generic, Lift_Generic)]
 #[cfg_attr(
     feature = "nightly",