diff --git a/divio_cli/localdev/main.py b/divio_cli/localdev/main.py
index c401b98..213ac83 100644
--- a/divio_cli/localdev/main.py
+++ b/divio_cli/localdev/main.py
@@ -920,7 +920,7 @@ def develop_package(package, no_rebuild=False):
     requirements_file = os.path.join(project_home, "requirements.in")
     # open file with 'universal newline support'
     # https://docs.python.org/2/library/functions.html#open
-    with open(requirements_file, "rU") as fh:
+    with open(requirements_file, "r") as fh:
         addons = fh.readlines()
 
     replaced = False