diff --git a/python/dune/perftool/sumfact/basis.py b/python/dune/perftool/sumfact/basis.py
index 892cfd125249d22462ebd75617dcd9850b077332..1f15491e9abc88041f293f21d4abb562aa21a827 100644
--- a/python/dune/perftool/sumfact/basis.py
+++ b/python/dune/perftool/sumfact/basis.py
@@ -90,6 +90,9 @@ def pymbolic_coefficient_gradient(element, restriction, component, coeff_func, v
         from dune.perftool.sumfact.vectorization import attach_vectorization_info
         sf = attach_vectorization_info(sf)
 
+        if i != sf.index:
+            direct_indexing_is_possible = False
+
         # Add a sum factorization kernel that implements the
         # evaluation of the gradients of basis functions at quadrature
         # points (stage 1)