diff --git a/tests/tests.cpp b/tests/tests.cpp
index e6c1b25e..50f1aa21 100644
--- a/tests/tests.cpp
+++ b/tests/tests.cpp
@@ -328,6 +328,7 @@ test_mknod_ff()
   Func2::MknodFF mknod;
   Branches branches;
 
+  branches.from_string("/tmp/a:/tmp/b");
 }
 
 TEST_LIST =