diff --git a/lsmtool/skymodel.py b/lsmtool/skymodel.py
index 920f4eeabe4817619c6a117f4fcca222bcfb74bf..e1503d3d656b05061bbd784fe76a89da4a93683b 100644
--- a/lsmtool/skymodel.py
+++ b/lsmtool/skymodel.py
@@ -2075,7 +2075,7 @@ class SkyModel(object):
             >>> s.group('tessellate', targetFlux=30.0)
 
         """
-        operations.group.group(self, algorithm, targetFlux=targetFlux, weightBySize=weightBySize
+        operations.group.group(self, algorithm, targetFlux=targetFlux, weightBySize=weightBySize,
                                numClusters=numClusters, FWHM=FWHM, threshold=threshold,
                                applyBeam=applyBeam, root=root, pad_index=pad_index,
                                method=method, facet=facet, byPatch=byPatch,