diff --git a/test/test_loopy.py b/test/test_loopy.py
index 8c46e52d7dc0c8a0cb002c6e3094cb58c047bb3c..c43e06a8c62b72e33721f0afa40b7d31241aec67 100644
--- a/test/test_loopy.py
+++ b/test/test_loopy.py
@@ -1960,8 +1960,8 @@ def test_integer_reduction(ctx_factory):
 
         for reduction, function in reductions:
             kstr = (("out" if 'arg' not in reduction
-                else "out[0], out[1]") + ' = {}(k, var[k])'.format(reduction))
-            knl = lp.make_kernel('{[k]: 0<=k<n}}',
+                else "out[0], out[1]") + ' = %s(k, var[k])' % reduction)`
+            knl = lp.make_kernel('{[k]: 0<=k<n}',
                                 kstr,
                                 [var_lp, '...'])