diff --git a/in/gen_drs_mutex.py b/in/gen_drs_mutex.py
index 621c40a..35188c0 100755
--- a/in/gen_drs_mutex.py
+++ b/in/gen_drs_mutex.py
@@ -33,7 +33,7 @@ context-automaton {{
 """
 
 PROPERTY_STR = """
-rsctlk-property {{ {:s} }}
+rsctlk-property {{ default : {:s} }}
 """