diff --git a/src/libexpr/eval-cache.cc b/src/libexpr/eval-cache.cc
index dbfd8e70b..0d83b6cfe 100644
--- a/src/libexpr/eval-cache.cc
+++ b/src/libexpr/eval-cache.cc
@@ -486,7 +486,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
                         return nullptr;
                     else if (std::get_if<failed_t>(&attr->second)) {
                         if (forceErrors)
-                            debug("reevaluating failed cached attribute '%s'");
+                            debug("reevaluating failed cached attribute '%s'", getAttrPathStr(name));
                         else
                             throw CachedEvalError("cached failure of attribute '%s'", getAttrPathStr(name));
                     } else