diff --git a/src/libexpr-tests/error_traces.cc b/src/libexpr-tests/error_traces.cc
index be379a909..011a0848d 100644
--- a/src/libexpr-tests/error_traces.cc
+++ b/src/libexpr-tests/error_traces.cc
@@ -712,7 +712,7 @@ namespace nix {
 
         ASSERT_TRACE1("head []",
                       Error,
-                      HintFmt("list index %d is out of bounds", 0));
+                      HintFmt("'head' called on an empty list"));
 
     }