diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 1edfe19ee..676bfbbbe 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -647,7 +647,7 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
     printInfo("finding garbage collector roots...");
     Roots rootMap;
     if (!options.ignoreLiveness)
-        findRootsNoTemp(rootMap, true);
+        rootMap = findRoots(true);
 
     for (auto & i : rootMap) roots.insert(i.first);