diff --git a/src/librustc/ty/subst.rs b/src/librustc/ty/subst.rs
index b8ae0430502b5..9ac3fc2da55e7 100644
--- a/src/librustc/ty/subst.rs
+++ b/src/librustc/ty/subst.rs
@@ -541,6 +541,8 @@ impl<'a, 'gcx, 'tcx> SubstFolder<'a, 'gcx, 'tcx> {
         let opt_ty = self.substs.get(p.idx as usize).map(|k| k.unpack());
         let ty = match opt_ty {
             Some(UnpackedKind::Type(ty)) => ty,
+            Some(UnpackedKind::Const(ty::Const { ty, ..})) => ty,
+            None => source_ty,
             _ => {
                 let span = self.span.unwrap_or(DUMMY_SP);
                 span_bug!(
@@ -551,7 +553,8 @@ impl<'a, 'gcx, 'tcx> SubstFolder<'a, 'gcx, 'tcx> {
                     source_ty,
                     p.idx,
                     self.root_ty,
-                    self.substs);
+                    self.substs,
+                );
             }
         };
 
diff --git a/src/test/ui/const-generics/issue-60264.rs b/src/test/ui/const-generics/issue-60264.rs
new file mode 100644
index 0000000000000..28c9cad6ca7ed
--- /dev/null
+++ b/src/test/ui/const-generics/issue-60264.rs
@@ -0,0 +1,8 @@
+use std::marker::PhantomData;
+
+struct B<T = N, const N: T>(PhantomData<[T; N]>);
+//~^ ERROR expected type, found const parameter `N`
+//~| ERROR const generics are unstable
+//~| ERROR mismatched types
+
+fn main() {}
diff --git a/src/test/ui/const-generics/issue-60264.stderr b/src/test/ui/const-generics/issue-60264.stderr
new file mode 100644
index 0000000000000..3219a0ce94dd0
--- /dev/null
+++ b/src/test/ui/const-generics/issue-60264.stderr
@@ -0,0 +1,28 @@
+error[E0573]: expected type, found const parameter `N`
+  --> $DIR/issue-60264.rs:3:14
+   |
+LL | struct B<T = N, const N: T>(PhantomData<[T; N]>);
+   |              ^ help: a struct with a similar name exists: `B`
+
+error[E0658]: const generics are unstable
+  --> $DIR/issue-60264.rs:3:23
+   |
+LL | struct B<T = N, const N: T>(PhantomData<[T; N]>);
+   |                       ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/44580
+   = help: add #![feature(const_generics)] to the crate attributes to enable
+
+error[E0308]: mismatched types
+  --> $DIR/issue-60264.rs:3:45
+   |
+LL | struct B<T = N, const N: T>(PhantomData<[T; N]>);
+   |                                             ^ expected usize, found type parameter
+   |
+   = note: expected type `usize`
+              found type `T`
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0308, E0658.
+For more information about an error, try `rustc --explain E0308`.