diff --git a/examples_ptx/radixSort/Makefile_gpu b/examples_ptx/radixSort/Makefile_gpu
index bc1c1d67..4e101992 100644
--- a/examples_ptx/radixSort/Makefile_gpu
+++ b/examples_ptx/radixSort/Makefile_gpu
@@ -1,6 +1,6 @@
 PROG=radixSort
 ISPC_SRC=radixSort.ispc
-#CU_SRC=radixSort.cu
+CU_SRC=radixSort.cu
 CXX_SRC=radixSort.cpp  radixSort.cpp
 PTXCC_REGMAX=64