diff --git a/setup.py b/setup.py
index c232f1f..3a793ec 100644
--- a/setup.py
+++ b/setup.py
@@ -18,7 +18,7 @@ my_extension = setuptools.Extension(
     "pywikidiff2",
     sources=cpp_sources,
     include_dirs=[],
-    extra_compile_args=["-Wall", "-std=c++17", "-fPIC","-lthai","-lstdc++"],
+    extra_compile_args=["-Wall", "-std=c++17", "-fPIC","-lthai","-lstdc++", "-O3"],
     extra_link_args=["-lthai", "-lstdc++","-fPIC"],
     language="c++",
 )