diff --git a/modules/bindings/pymod/msms.py b/modules/bindings/pymod/msms.py
index 1d260de4b1aa41335c75a762924fb6888fca1bd9..d928f6c57ae1ddcdd8abd0f1af3d3163e070eac0 100644
--- a/modules/bindings/pymod/msms.py
+++ b/modules/bindings/pymod/msms.py
@@ -197,7 +197,7 @@ def CalculateSurfaceArea(entity, density=1.0, radius=1.5,  all_surf=False,
   if all_surf:
     command+=" -all"
   if attach_asa != None:
-      command+=" -af %s" % os.path.join(msms_data_dir, "asa_atom")
+    command+=" -af %s" % os.path.join(msms_data_dir, "asa_atom")
   # run msms
   stdout_value=_RunMSMS(command)