diff --git a/python/dune/perftool/pdelab/driver.py b/python/dune/perftool/pdelab/driver.py
index 22e56115cc9c4fad34eecd3c951d7d15989cd452..aaf4c092503cbf76ab8747bd1d70dadf34a85e8d 100644
--- a/python/dune/perftool/pdelab/driver.py
+++ b/python/dune/perftool/pdelab/driver.py
@@ -1427,7 +1427,7 @@ def setup_timer():
 @preamble
 def define_timing_identifier(name):
     ini = name_initree()
-    return "auto {} = {}.get<std::string>(\"identifier\", std::string(argv[0])).c_str();".format(name, ini)
+    return "auto {} = {}.get<std::string>(\"identifier\", std::string(argv[0]));".format(name, ini)
 
 
 def name_timing_identifier():