diff --git a/src/unasync/__init__.py b/src/unasync/__init__.py
index 80845ff..92be78d 100644
--- a/src/unasync/__init__.py
+++ b/src/unasync/__init__.py
@@ -78,7 +78,9 @@ def _unasync_file(self, filepath):
             tokens = _tokenize(f)
             tokens = self._unasync_tokens(tokens)
             result = _untokenize(tokens)
-            result = self._unasync_remove(contents=result, filename=filepath)
+            # Limit to Python3.8+ until we know how to support older versions
+            if (sys.version_info[0] == 3 and sys.version_info[1] >= 8) or sys.version_info[0] > 3:
+                result = self._unasync_remove(contents=result, filename=filepath)
             outfilepath = filepath.replace(self.fromdir, self.todir)
             _makedirs_existok(os.path.dirname(outfilepath))
             with open(outfilepath, "w", **write_kwargs) as f: