diff --git a/tests/issues.cpp b/tests/issues.cpp
index db42783..429e2f5 100644
--- a/tests/issues.cpp
+++ b/tests/issues.cpp
@@ -77,6 +77,6 @@ TEST_CASE("Issue 31", "[issues.31]") {
 TEST_CASE("Issue 33", "[issues.33]") {
     tl::expected<void, int> res {tl::unexpect, 0};
     REQUIRE(!res);    
-    res = res.map_error([](auto i) { return 42; });
+    res = res.map_error([](int i) { return 42; });
     REQUIRE(res.error() == 42);
 }