diff --git a/python/dune/perftool/sumfact/basis.py b/python/dune/perftool/sumfact/basis.py
index a7b3c4c98ac3c5b262ff1f7dee9b5acecba33aa9..40f042ef96f1cf167487008d3e07b1cfe61374e6 100644
--- a/python/dune/perftool/sumfact/basis.py
+++ b/python/dune/perftool/sumfact/basis.py
@@ -247,9 +247,9 @@ def evaluate_reference_gradient(element, name, restriction):
     i = 0
     for d in range(local_dimension()):
         if d == facedir:
-            i = i+1
+            i = i + 1
         quadinamemapping[i] = quad_inames[d]
-        i = i+1
+        i = i + 1
 
     for d in range(dim):
         prod = []
@@ -261,7 +261,7 @@ def evaluate_reference_gradient(element, name, restriction):
         if facedir is not None:
             facemod = get_facemod(restriction)
             from dune.perftool.sumfact.amatrix import PolynomialLookup, name_polynomials
-            prod.append(prim.Call(PolynomialLookup(name_polynomials(), facedir==d),
+            prod.append(prim.Call(PolynomialLookup(name_polynomials(), facedir == d),
                                   (prim.Variable(inames[facedir]), facemod)),)
 
         assignee = prim.Subscript(prim.Variable(name), (d,))