diff --git a/src/refine.rs b/src/refine.rs
index 5a1fd8d3..8669cda4 100644
--- a/src/refine.rs
+++ b/src/refine.rs
@@ -33,7 +33,7 @@ fn stable_def_id_symbol(tcx: mir_ty::TyCtxt<'_>, did: DefId) -> String {
 }
 
 pub fn datatype_symbol(tcx: mir_ty::TyCtxt<'_>, did: DefId) -> DatatypeSymbol {
-    DatatypeSymbol::new(tcx.def_path_str(did).replace("::", "."))
+    DatatypeSymbol::new(stable_def_id_symbol(tcx, did))
 }
 
 pub fn user_defined_pred(tcx: mir_ty::TyCtxt<'_>, did: DefId) -> UserDefinedPred {
diff --git a/tests/ui/fail/enum_local_in_trait_impl.rs b/tests/ui/fail/enum_local_in_trait_impl.rs
new file mode 100644
index 00000000..eccd3611
--- /dev/null
+++ b/tests/ui/fail/enum_local_in_trait_impl.rs
@@ -0,0 +1,56 @@
+//@error-in-other-file: Unsat
+//@compile-flags: -C debug-assertions=off
+
+trait T {
+    fn f(b: bool) -> i64;
+}
+
+struct A;
+struct B;
+
+impl thrust_models::Model for A {
+    type Ty = Self;
+}
+
+impl thrust_models::Model for B {
+    type Ty = Self;
+}
+
+impl T for A {
+    fn f(b: bool) -> i64 {
+        enum E {
+            X(i64),
+            Y,
+        }
+        impl thrust_models::Model for E {
+            type Ty = Self;
+        }
+        let e = if b { E::X(1) } else { E::Y };
+        match e {
+            E::X(x) => x,
+            E::Y => 0,
+        }
+    }
+}
+
+impl T for B {
+    fn f(b: bool) -> i64 {
+        enum E {
+            Z(bool),
+            W(i64),
+        }
+        impl thrust_models::Model for E {
+            type Ty = Self;
+        }
+        let e = if b { E::Z(true) } else { E::W(5) };
+        match e {
+            E::Z(_) => 10,
+            E::W(v) => v,
+        }
+    }
+}
+
+fn main() {
+    assert!(A::f(true) == 1);
+    assert!(B::f(false) == 10);
+}
diff --git a/tests/ui/pass/enum_local_in_trait_impl.rs b/tests/ui/pass/enum_local_in_trait_impl.rs
new file mode 100644
index 00000000..a2644a07
--- /dev/null
+++ b/tests/ui/pass/enum_local_in_trait_impl.rs
@@ -0,0 +1,56 @@
+//@check-pass
+//@compile-flags: -C debug-assertions=off
+
+trait T {
+    fn f(b: bool) -> i64;
+}
+
+struct A;
+struct B;
+
+impl thrust_models::Model for A {
+    type Ty = Self;
+}
+
+impl thrust_models::Model for B {
+    type Ty = Self;
+}
+
+impl T for A {
+    fn f(b: bool) -> i64 {
+        enum E {
+            X(i64),
+            Y,
+        }
+        impl thrust_models::Model for E {
+            type Ty = Self;
+        }
+        let e = if b { E::X(1) } else { E::Y };
+        match e {
+            E::X(x) => x,
+            E::Y => 0,
+        }
+    }
+}
+
+impl T for B {
+    fn f(b: bool) -> i64 {
+        enum E {
+            Z(bool),
+            W(i64),
+        }
+        impl thrust_models::Model for E {
+            type Ty = Self;
+        }
+        let e = if b { E::Z(true) } else { E::W(5) };
+        match e {
+            E::Z(_) => 10,
+            E::W(v) => v,
+        }
+    }
+}
+
+fn main() {
+    assert!(A::f(true) == 1);
+    assert!(B::f(false) == 5);
+}