diff --git a/DDRec/python/DDRec.py b/DDRec/python/DDRec.py
index a8910f76974d7e648a5b2df7d69840de2f4aedfc..d25ca59976c40682e53619015bd2defddbb46a74 100644
--- a/DDRec/python/DDRec.py
+++ b/DDRec/python/DDRec.py
@@ -98,5 +98,5 @@ def import_rec():
 
 # Now instantiate the entire thing
 import_rec()
-std_list_ISurface = core.std_list('ISurface*')
-std_list_VolSurface = core.std_list('VolSurface')
+std_list_ISurface = core.std_list(str('ISurface*'))
+std_list_VolSurface = core.std_list(str('VolSurface'))