diff --git a/setup.py b/setup.py
index 1ae577ba4..eb8bb43a0 100755
--- a/setup.py
+++ b/setup.py
@@ -630,7 +630,8 @@ class pil_build_ext(build_ext):
         exts = [(Extension("PIL._imaging",
                            files,
                            libraries=libs,
-                           define_macros=defs))]
+                           define_macros=defs,
+                           extra_compile_args=['-msse4']))]
 
         #
         # additional libraries