diff --git a/src/cal_tools/gotthard2/gotthard2lib.py b/src/cal_tools/gotthard2/gotthard2lib.py
index 061bea183c596e4cd48efbe250ec4f07bdabadc9..8b24818332c419c44a6a5a4db5abca5aaa28c6f1 100644
--- a/src/cal_tools/gotthard2/gotthard2lib.py
+++ b/src/cal_tools/gotthard2/gotthard2lib.py
@@ -42,7 +42,7 @@ class Gotthard2Ctrl():
 
     def get_single_photon(self):
         """Get single photon for gotthard2."""
-        if "singlePhoton.value" in self.run_dc.keys_for_source(self.ctrl_src):
+        if "singlePhoton" in self.run_dc[self.ctrl_src]:
             return bool(
                 self.run_dc[self.ctrl_src, "singlePhoton"].as_single_value())