diff --git a/mmdet/ops/nms/Makefile b/mmdet/ops/nms/Makefile
index 39556dd28ba76300d0f491cd5e66d4a4d19fc8ee..af511f343f6f9e9b426544b6c567d773556a65d8 100644
--- a/mmdet/ops/nms/Makefile
+++ b/mmdet/ops/nms/Makefile
@@ -5,4 +5,4 @@ all:
 	$(PYTHON) setup.py build_ext --inplace
 
 clean:
-	rm *.so
+	rm -f *.so
diff --git a/mmdet/ops/nms/setup.py b/mmdet/ops/nms/setup.py
index 98bf57c8f135805927205ec638d865177b070d8c..a8fe373d585336c1af6540cfcd2eec25e93c90b4 100644
--- a/mmdet/ops/nms/setup.py
+++ b/mmdet/ops/nms/setup.py
@@ -1,41 +1,24 @@
-import os
-from distutils.core import setup
-from distutils.extension import Extension
+import os.path as osp
+from distutils.core import setup, Extension
 
 import numpy as np
 from Cython.Build import cythonize
 from Cython.Distutils import build_ext
 
-CUDA_ROOT = '/usr/local/cuda'
-CUDA = {
-    "include": os.path.join(CUDA_ROOT, 'include'),
-    "lib": os.path.join(CUDA_ROOT, 'lib64'),
-    "nvcc": os.path.join(CUDA_ROOT, 'bin', "nvcc")
-}
-
-inc_dirs = [CUDA['include'], np.get_include()]
-
-lib_dirs = [CUDA['lib']]
-
 # extensions
 ext_args = dict(
-    include_dirs=inc_dirs,
-    library_dirs=lib_dirs,
+    include_dirs=[np.get_include()],
     language='c++',
-    libraries=['cudart'],
     extra_compile_args={
-        "cc": ['-Wno-unused-function', '-Wno-write-strings'],
-        "nvcc": [
-            '-arch=sm_52', '--ptxas-options=-v', '-c', '--compiler-options',
-            '-fPIC'
-        ],
+        'cc': ['-Wno-unused-function', '-Wno-write-strings'],
+        'nvcc': ['-c', '--compiler-options', '-fPIC'],
     },
 )
 
 extensions = [
     Extension('cpu_nms', ['cpu_nms.pyx'], **ext_args),
-    Extension('gpu_nms', ['gpu_nms.pyx', 'nms_kernel.cu'], **ext_args),
     Extension('cpu_soft_nms', ['cpu_soft_nms.pyx'], **ext_args),
+    Extension('gpu_nms', ['gpu_nms.pyx', 'nms_kernel.cu'], **ext_args),
 ]
 
 
@@ -59,9 +42,9 @@ def customize_compiler_for_nvcc(self):
     # object but distutils doesn't have the ability to change compilers
     # based on source extension: we add it.
     def _compile(obj, src, ext, cc_args, extra_postargs, pp_opts):
-        if os.path.splitext(src)[1] == '.cu':
+        if osp.splitext(src)[1] == '.cu':
             # use the cuda for .cu files
-            self.set_executable('compiler_so', CUDA['nvcc'])
+            self.set_executable('compiler_so', 'nvcc')
             # use only a subset of the extra_postargs, which are 1-1 translated
             # from the extra_compile_args in the Extension class
             postargs = extra_postargs['nvcc']