diff --git a/thrust/testing/tuple_reduce.cu b/thrust/testing/tuple_reduce.cu
index c7f7a42f7dc..2bcfab751a7 100644
--- a/thrust/testing/tuple_reduce.cu
+++ b/thrust/testing/tuple_reduce.cu
@@ -38,7 +38,7 @@ struct TestTupleReduce
 
     // zip up the data
     host_vector<tuple<T, T>> h_tuples(n);
-    transform(h_t1.begin(), h_t1.end(), h_t2.begin(), h_tuples.begin(), MakeTupleFunctor());
+    thrust::transform(h_t1.begin(), h_t1.end(), h_t2.begin(), h_tuples.begin(), MakeTupleFunctor());
 
     // copy to device
     device_vector<tuple<T, T>> d_tuples = h_tuples;