diff --git a/requirements.txt b/requirements.txt
index 891c857..d28820a 100755
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,6 +3,7 @@ keras-preprocessing == 1.1.0
 numpy >= 1.15.4
 ocrd >= 2.22.3
 ocrd-fork-pylsd >= 0.0.4
+ocrd-fork-ocropy >= 1.4.0a3 # Python3 ocrolib
 opencv-python-headless >= 3.4
 pandas
 scikit-image >= 0.17.2