diff --git a/src/cal_tools/calcat_interface2.py b/src/cal_tools/calcat_interface2.py
index d312f5bef2bfb97f0cf75f1a41c475a4c332ab89..6a52f730fc3597975a0d06c45c5ec3f7274e8f6f 100644
--- a/src/cal_tools/calcat_interface2.py
+++ b/src/cal_tools/calcat_interface2.py
@@ -341,7 +341,7 @@ class CalibrationData(Mapping):
 
     def __init__(self, constant_groups, module_details):
         self.constant_groups = {
-            const_type: ModulesConstantVersions(d)
+            const_type: ModulesConstantVersions(d, module_details)
             for const_type, d in constant_groups.items()
         }
         self.module_details = module_details