diff --git a/src/analyze/local_def.rs b/src/analyze/local_def.rs
index 6a9cdf1b..6e9acc38 100644
--- a/src/analyze/local_def.rs
+++ b/src/analyze/local_def.rs
@@ -415,6 +415,14 @@ impl<'tcx, 'ctx> Analyzer<'tcx, 'ctx> {
             return Some((lhs_local, *place));
         }
 
+        // GVN rewrites the deref temp of a `&mut` from `deref_copy` into a plain `copy`.
+        if let mir::Rvalue::Use(mir::Operand::Copy(place)) = &rvalue {
+            let ty = place.ty(&self.body.local_decls, self.tcx).ty;
+            if !place.projection.is_empty() && ty.ref_mutability() == Some(mir::Mutability::Mut) {
+                return Some((lhs_local, *place));
+            }
+        }
+
         let unique_did = self.ctx.def_ids.unique()?;
         let nonnull_did = self.ctx.def_ids.nonnull()?;
 
diff --git a/tests/ui/fail/mut_ref_deref_optimized.rs b/tests/ui/fail/mut_ref_deref_optimized.rs
new file mode 100644
index 00000000..8b092d39
--- /dev/null
+++ b/tests/ui/fail/mut_ref_deref_optimized.rs
@@ -0,0 +1,13 @@
+//@error-in-other-file: Unsat
+//@compile-flags: -C debug-assertions=off -C opt-level=1
+
+fn bump(w: &mut &mut i64) {
+    **w += 3;
+}
+
+fn main() {
+    let mut a = 0;
+    let mut r = &mut a;
+    bump(&mut r);
+    assert!(a == 0);
+}
diff --git a/tests/ui/pass/mut_ref_deref_optimized.rs b/tests/ui/pass/mut_ref_deref_optimized.rs
new file mode 100644
index 00000000..1fe48759
--- /dev/null
+++ b/tests/ui/pass/mut_ref_deref_optimized.rs
@@ -0,0 +1,13 @@
+//@check-pass
+//@compile-flags: -C debug-assertions=off -C opt-level=1
+
+fn bump(w: &mut &mut i64) {
+    **w += 3;
+}
+
+fn main() {
+    let mut a = 0;
+    let mut r = &mut a;
+    bump(&mut r);
+    assert!(a == 3);
+}