diff --git a/include/mettle/detail/source_location_shim.hpp b/include/mettle/detail/source_location_shim.hpp
index d0dc232..b1d624e 100644
--- a/include/mettle/detail/source_location_shim.hpp
+++ b/include/mettle/detail/source_location_shim.hpp
@@ -20,6 +20,7 @@ namespace mettle::detail {
 
     static source_location_shim current(
 #ifdef METTLE_NO_SOURCE_LOCATION
+#  error "Oops, no source_location!"
       const char *file = "unknown",
       const char *func = "unknown",
       std::uint_least32_t line = 0,