diff --git a/CMakeLists.txt b/CMakeLists.txt
index d8ef0473..2a182a49 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -347,12 +347,15 @@ IF(ENABLE_CUDA)
     SET(LIBFREENECT2_WITH_CUDA_SUPPORT 1)
     SET(HAVE_CUDA yes)
 
-    STRING(REPLACE "\\" "/" NVCUDASAMPLES_ROOT "$ENV{NVCUDASAMPLES_ROOT}")
+    IF(NOT DEFINED NVCUDASAMPLES_ROOT)
+      STRING(REPLACE "\\" "/" NVCUDASAMPLES_ROOT "$ENV{NVCUDASAMPLES_ROOT}")
+    ENDIF()
     STRING(REPLACE "\\" "/" NVCUDASAMPLES8_0_ROOT "$ENV{NVCUDASAMPLES8_0_ROOT}")
     CUDA_INCLUDE_DIRECTORIES(
       "${MY_DIR}/include/"
       "${CUDA_TOOLKIT_ROOT_DIR}/samples/common/inc"
       "${NVCUDASAMPLES_ROOT}/common/inc"
+      "${NVCUDASAMPLES_ROOT}/Common"
       "${NVCUDASAMPLES8_0_ROOT}/common/inc"
     )
     SET(CUDA_FLAGS -use_fast_math)
diff --git a/README.md b/README.md
index 3bde4ceb..b7d84795 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,15 @@ When you report USB issues, please attach relevant debug log from running the pr
 
 ## Installation
 
+### Enable CUDA (optional)
+
+Install the latest CUDA Toolkit. Add option `-DENABLE_CUDA=ON -DNVCUDASAMPLES_ROOT=<cuda_samples_dir>` to cmake to enable CUDA. CUDA samples could be downloaded [here](https://github.com/NVIDIA/cuda-samples.git). Below is an example to build on Linux if you download CUDA samples under the same directory as libfreenect2:
+
+``` sh
+cd libfreenect2 && mkdir build && cd build
+cmake .. -DENABLE_CXX11=ON -DENABLE_CUDA=ON -DNVCUDASAMPLES_ROOT=`pwd`/../../cuda-samples && make -j4
+```
+
 ### Windows / Visual Studio
 
 * Install UsbDk driver