diff --git a/src/store.cc b/src/store.cc
index 6157b4bc22..65c44ca37f 100644
--- a/src/store.cc
+++ b/src/store.cc
@@ -151,7 +151,7 @@ void unregisterPath(const string & _path)
 bool queryPathId(const string & path, FSId & id)
 {
     string s;
-    if (!queryDB(nixDB, dbPath2Id, path, s)) return false;
+    if (!queryDB(nixDB, dbPath2Id, absPath(path), s)) return false;
     id = parseHash(s);
     return true;
 }