diff --git a/setup.py b/setup.py
old mode 100755
new mode 100644
index dad12e40..fb1054be
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@ def run_tests(self):
     packages=[
         'pyhocon',
     ],
-    install_requires=['pyparsing~=2.0'],
+    install_requires=['pyparsing>=2,<4'],
     extras_require={
         'Duration': ['python-dateutil>=2.8.0']
     },