diff --git a/absl/base/casts.h b/absl/base/casts.h
index 20fd34da..1eef6a61 100644
--- a/absl/base/casts.h
+++ b/absl/base/casts.h
@@ -105,7 +105,7 @@ struct is_bitcastable
 //
 // Such implicit cast chaining may be useful within template logic.
 template <typename To>
-inline To implicit_cast(typename absl::internal::identity_t<To> to) {
+constexpr To implicit_cast(typename absl::internal::identity_t<To> to) {
   return to;
 }