diff --git a/test/test_array.py b/test/test_array.py
index 65b98038db2b09ac8cac865e9fb03d275b164d96..381105bf8a3fc7cbeea70b658e863cb0efe6df99 100644
--- a/test/test_array.py
+++ b/test/test_array.py
@@ -212,7 +212,7 @@ def test_zeros_large_array(ctx_factory):
     if queue.device.address_bits == 64:
         # this shouldn't hang/cause errors
         # see https://github.com/inducer/pyopencl/issues/395
-        a_gpu = cl_array.zeros(queue, (2**28 + 1,), dtype='float64')
+        a_gpu = cl_array.zeros(queue, (2**28 + 1,), dtype="float64")
         # run a couple kernels to ensure no propagated runtime errors
         a_gpu[...] = 1.
         a_gpu = 2 * a_gpu - 3