diff --git a/cpmpy/transformations/decompose_global.py b/cpmpy/transformations/decompose_global.py
index 4e89ae07b..7548aede1 100644
--- a/cpmpy/transformations/decompose_global.py
+++ b/cpmpy/transformations/decompose_global.py
@@ -47,8 +47,9 @@ def decompose_in_tree(lst_of_expr, supported=set(), supported_reified=set(), _to
             continue
 
         elif isinstance(expr, Operator):
-            expr, base_con = normalized_numexpr(expr)
-            _toplevel.extend(base_con)  # should be added toplevel
+            if any(isinstance(a,GlobalFunction) for a in expr.args):
+                expr, base_con = normalized_numexpr(expr)
+                _toplevel.extend(base_con)  # should be added toplevel
             # recurse into arguments, recreate through constructor (we know it stores no other state)
             args = decompose_in_tree(expr.args, supported, supported_reified, _toplevel, nested=True)
             newlist.append(Operator(expr.name, args))