diff --git a/setup.py b/setup.py
index 1325cfe56737e8adf3c7a43e0878f4810d2cdde6..38de346662d81f0e08d79bd5687d597f2d2ab512 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@ setup(
     Extension("groupConnectivity",
       sources = ["groupConnectivity.pyx"],
       language="c++",
-      extra_compile_args=["-std=gnu++11", "-O2"]
+      extra_compile_args=["-std=gnu++11", "-O2", "-funroll-loops"]
     )
   ])
 )