diff --git a/src/analyze/local_def.rs b/src/analyze/local_def.rs
index 6a9cdf1b..366eaf85 100644
--- a/src/analyze/local_def.rs
+++ b/src/analyze/local_def.rs
@@ -232,11 +232,9 @@ impl<'tcx, 'ctx> Analyzer<'tcx, 'ctx> {
     // `def_ty_with_args` directly.
     fn precompute_callable_param_contracts(&mut self, sig: &mir_ty::FnSig<'tcx>) {
         for input_ty in sig.inputs() {
-            let inst =
-                mir_ty::EarlyBinder::bind(*input_ty).instantiate(self.tcx, self.generic_args);
             let inst = self
                 .tcx
-                .normalize_erasing_regions(mir_ty::TypingEnv::fully_monomorphized(), inst);
+                .normalize_erasing_regions(mir_ty::TypingEnv::fully_monomorphized(), *input_ty);
             let (fn_def_id, fn_args) = match inst.kind() {
                 mir_ty::TyKind::Closure(def_id, args) => {
                     (*def_id, self.tcx.mk_args(args.as_closure().parent_args()))
diff --git a/tests/ui/fail/trait_impl_lifetime_param.rs b/tests/ui/fail/trait_impl_lifetime_param.rs
new file mode 100644
index 00000000..bafe10a8
--- /dev/null
+++ b/tests/ui/fail/trait_impl_lifetime_param.rs
@@ -0,0 +1,33 @@
+//@error-in-other-file: Unsat
+//@compile-flags: -C debug-assertions=off
+
+#[thrust_macros::context]
+trait Get {
+    #[thrust_macros::requires(true)]
+    #[thrust_macros::ensures(result >= 0)]
+    fn get(&self) -> i64;
+}
+
+struct R<'a> {
+    r: &'a i64,
+}
+
+impl<'a> thrust_models::Model for R<'a> {
+    type Ty = Self;
+}
+
+impl<'a> Get for R<'a> {
+    fn get(&self) -> i64 {
+        if *self.r >= 0 {
+            *self.r
+        } else {
+            -1
+        }
+    }
+}
+
+fn main() {
+    let x = 5;
+    let r = R { r: &x };
+    assert!(r.get() >= 0);
+}
diff --git a/tests/ui/pass/trait_impl_lifetime_param.rs b/tests/ui/pass/trait_impl_lifetime_param.rs
new file mode 100644
index 00000000..9f86f7b1
--- /dev/null
+++ b/tests/ui/pass/trait_impl_lifetime_param.rs
@@ -0,0 +1,33 @@
+//@check-pass
+//@compile-flags: -C debug-assertions=off
+
+#[thrust_macros::context]
+trait Get {
+    #[thrust_macros::requires(true)]
+    #[thrust_macros::ensures(result >= 0)]
+    fn get(&self) -> i64;
+}
+
+struct R<'a> {
+    r: &'a i64,
+}
+
+impl<'a> thrust_models::Model for R<'a> {
+    type Ty = Self;
+}
+
+impl<'a> Get for R<'a> {
+    fn get(&self) -> i64 {
+        if *self.r >= 0 {
+            *self.r
+        } else {
+            0
+        }
+    }
+}
+
+fn main() {
+    let x = 5;
+    let r = R { r: &x };
+    assert!(r.get() >= 0);
+}