diff --git a/setup.py b/setup.py
index 2e8081e..ab343ad 100644
--- a/setup.py
+++ b/setup.py
@@ -156,9 +156,9 @@ class BuildCMakeExt(build_ext):
 
         cython_code = os.path.join(str(build_dir.absolute()),'mycython')
         with open(cython_code, mode="wt") as ff:
-          ff.write(f"#!/usr/bin/env sh -c '${PYTHON}'\n"
-                    "from Cython.Compiler.Main import setuptools_main\n"
-                    "setuptools_main()")
+          ff.write("#!/usr/bin/env sh -c '${PYTHON}'\n"
+                   "from Cython.Compiler.Main import setuptools_main\n"
+                   "setuptools_main()")
         os.chmod(cython_code, stat.S_IXUSR|stat.S_IWUSR|stat.S_IRUSR|stat.S_IRGRP)
 
         # Now that the necessary directories are created, build