diff --git a/include/boost/compute/algorithm/transform_if.hpp b/include/boost/compute/algorithm/transform_if.hpp
index 0eb0fd43..26e14411 100644
--- a/include/boost/compute/algorithm/transform_if.hpp
+++ b/include/boost/compute/algorithm/transform_if.hpp
@@ -53,14 +53,12 @@ inline OutputIterator transform_if_impl(InputIterator first,
            << predicate(first[k1.get_global_id(0)]) << " ? 1 : 0;\n";
     k1.exec_1d(queue, 0, count);
 
-    // count number of elements to be copied
-    size_t copied_element_count =
-        ::boost::compute::count(indices.begin(), indices.end(), 1, queue);
-
     // scan indices
+    size_t copied_element_count = (indices.cend() - 1).read(queue);
     ::boost::compute::exclusive_scan(
         indices.begin(), indices.end(), indices.begin(), queue
     );
+    copied_element_count += (indices.cend() - 1).read(queue); // last scan element plus last mask element
 
     // copy values
     ::boost::compute::detail::meta_kernel k2("transform_if_do_copy");