diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 6f75bc2af4ec8..ca8b98849338b 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -29,7 +29,7 @@ use rustc_target::abi::{
 use std::hash::Hash;
 
 use super::{
-    err_ub, format_interp_error, machine::AllocMap, throw_ub, AllocId, CheckInAllocMsg,
+    err_ub, format_interp_error, machine::AllocMap, throw_ub, AllocId, AllocKind, CheckInAllocMsg,
     GlobalAlloc, ImmTy, Immediate, InterpCx, InterpResult, MPlaceTy, Machine, MemPlaceMeta, OpTy,
     Pointer, Projectable, Scalar, ValueVisitor,
 };
@@ -413,8 +413,6 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
             Ub(PointerOutOfBounds { .. }) => DanglingPtrOutOfBounds {
                 ptr_kind
             },
-            // This cannot happen during const-eval (because interning already detects
-            // dangling pointers), but it can happen in Miri.
             Ub(PointerUseAfterFree(..)) => DanglingPtrUseAfterFree {
                 ptr_kind,
             },
@@ -493,9 +491,17 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                     }
                 }
 
-                // Mutability check.
+                // Dangling and Mutability check.
+                let (size, _align, alloc_kind) = self.ecx.get_alloc_info(alloc_id);
+                if alloc_kind == AllocKind::Dead {
+                    // This can happen for zero-sized references. We can't have *any* references to non-existing
+                    // allocations though, interning rejects them all as the rest of rustc isn't happy with them...
+                    // so we throw an error, even though this isn't really UB.
+                    // A potential future alternative would be to resurrect this as a zero-sized allocation
+                    // (which codegen will then compile to an aligned dummy pointer anyway).
+                    throw_validation_failure!(self.path, DanglingPtrUseAfterFree { ptr_kind });
+                }
                 // If this allocation has size zero, there is no actual mutability here.
-                let (size, _align, _alloc_kind) = self.ecx.get_alloc_info(alloc_id);
                 if size != Size::ZERO {
                     let alloc_actual_mutbl = mutability(self.ecx, alloc_id);
                     // Mutable pointer to immutable memory is no good.
diff --git a/tests/ui/consts/dangling-alloc-id-ice.rs b/tests/ui/consts/dangling-alloc-id-ice.rs
index 6b07b8b3cc80d..76d6f33baf34b 100644
--- a/tests/ui/consts/dangling-alloc-id-ice.rs
+++ b/tests/ui/consts/dangling-alloc-id-ice.rs
@@ -10,7 +10,7 @@ union Foo<'a> {
 }
 
 const FOO: &() = {
-    //~^ ERROR encountered dangling pointer
+    //~^ ERROR it is undefined behavior to use this value
     let y = ();
     unsafe { Foo { y: &y }.long_live_the_unit }
 };
diff --git a/tests/ui/consts/dangling-alloc-id-ice.stderr b/tests/ui/consts/dangling-alloc-id-ice.stderr
index de31acf9fa441..881c0b162edca 100644
--- a/tests/ui/consts/dangling-alloc-id-ice.stderr
+++ b/tests/ui/consts/dangling-alloc-id-ice.stderr
@@ -1,8 +1,14 @@
-error: encountered dangling pointer in final value of constant
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/dangling-alloc-id-ice.rs:12:1
    |
 LL | const FOO: &() = {
-   | ^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^ constructing invalid value: encountered a dangling reference (use-after-free)
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
+               HEX_DUMP
+           }
 
 error: aborting due to 1 previous error
 
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/dangling-zst-ice-issue-126393.rs b/tests/ui/consts/dangling-zst-ice-issue-126393.rs
new file mode 100644
index 0000000000000..917aa0572fc0d
--- /dev/null
+++ b/tests/ui/consts/dangling-zst-ice-issue-126393.rs
@@ -0,0 +1,15 @@
+// Strip out raw byte dumps to make comparison platform-independent:
+//@ normalize-stderr-test "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)"
+//@ normalize-stderr-test "([0-9a-f][0-9a-f] |╾─*A(LLOC)?[0-9]+(\+[a-z0-9]+)?(<imm>)?─*╼ )+ *│.*" -> "HEX_DUMP"
+//@ normalize-stderr-test "HEX_DUMP\s*\n\s*HEX_DUMP" -> "HEX_DUMP"
+
+pub struct Wrapper;
+pub static MAGIC_FFI_REF: &'static Wrapper = unsafe {
+//~^ERROR: it is undefined behavior to use this value
+    std::mem::transmute(&{
+        let y = 42;
+        y
+    })
+};
+
+fn main() {}
diff --git a/tests/ui/consts/dangling-zst-ice-issue-126393.stderr b/tests/ui/consts/dangling-zst-ice-issue-126393.stderr
new file mode 100644
index 0000000000000..d32b427f14ef7
--- /dev/null
+++ b/tests/ui/consts/dangling-zst-ice-issue-126393.stderr
@@ -0,0 +1,14 @@
+error[E0080]: it is undefined behavior to use this value
+  --> $DIR/dangling-zst-ice-issue-126393.rs:7:1
+   |
+LL | pub static MAGIC_FFI_REF: &'static Wrapper = unsafe {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a dangling reference (use-after-free)
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
+               HEX_DUMP
+           }
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0080`.