diff --git a/extension_helpers/_setup_helpers.py b/extension_helpers/_setup_helpers.py
index ec3e547..e2419f7 100644
--- a/extension_helpers/_setup_helpers.py
+++ b/extension_helpers/_setup_helpers.py
@@ -79,8 +79,13 @@ def get_extensions(srcdir='.'):
     if len(ext_modules) > 0:
         main_package_dir = min(packages, key=len)
         src_path = os.path.join(os.path.dirname(__file__), 'src')
-        shutil.copy(os.path.join(src_path, 'compiler.c'),
-                    os.path.join(srcdir, main_package_dir, '_compiler.c'))
+        a = os.path.join(src_path, 'compiler.c')
+        b = os.path.join(srcdir, main_package_dir, '_compiler.c')
+        try:
+            os.unlink(b)
+        except OSError:
+            pass
+        shutil.copy(a, b)
         ext = Extension(main_package_dir + '.compiler_version',
                         [os.path.join(main_package_dir, '_compiler.c')])
         ext_modules.append(ext)