diff --git a/requirements.txt b/requirements.txt
index acb7db0b..159fccb9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ Flask-Principal>=0.3.2,<0.5.1
 backports_abc>=0.4
 Flask>=1.0.2,<2.3.0
 iso-639>=0.4.5,<0.5.0
-PyPDF<3.6.0
+PyPDF>=3.0.0,<3.6.0
 pytz>=2016.10
 requests>=2.11.1,<2.29.0
 SQLAlchemy>=1.3.0,<2.0.0