diff --git a/setup.py b/setup.py
index f019789..c2d1835 100644
--- a/setup.py
+++ b/setup.py
@@ -203,13 +203,13 @@ def __str__(self):
     elif sys.platform.startswith("darwin"):
         libraries_thread = None
         extra_compile_args_thread = ['-lpthread', '-stdlib=libc++', '-std=c++11',
-                                     '-mmacosx-version-min=10.7']  # , '-openmp']
+                                     '-mmacosx-version-min=10.7', '-fopenmp']
         extra_compile_args_numbers = ['-stdlib=libc++', '-mmacosx-version-min=10.7',
-                                      '-std=c++11']  # , '-openmp']
+                                      '-std=c++11', '-fopenmp']
         extra_compile_args_bench = extra_compile_args_numbers.copy()
         extra_compile_args_bench.append('-fpermissive')
-        extra_link_args = []  # ['-lomp']
-        define_macros = None
+        extra_link_args = ["-lomp"]
+        define_macros = [('USE_OPENMP', None)]
     else:
         libraries_thread = None
         extra_compile_args_thread = ['-lpthread', '-std=c++11', '-fopenmp']