diff --git a/requirements.txt b/requirements.txt
index ffcb5ca..aa6a0f0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,4 +20,5 @@ coverage==6.3.2
 Pillow==9.1.0
 PDFNetPython3==9.1.0
 pdf2image==1.16.0
-frozendict==2.3.0
\ No newline at end of file
+frozendict==2.3.0
+protobuf<=3.20.*
\ No newline at end of file