diff --git a/odl/operator/pspace_ops.py b/odl/operator/pspace_ops.py
index e1ddcd7802a..219cea714c1 100644
--- a/odl/operator/pspace_ops.py
+++ b/odl/operator/pspace_ops.py
@@ -263,7 +263,7 @@ def _convert_to_spmatrix(operators):
                     '{}'.format(len(row), i, ncols))
 
             for j, col in enumerate(row):
-                if col is None or col is 0:
+                if col is None or col == 0:
                     pass
                 elif isinstance(col, Operator):
                     irow.append(i)