diff --git a/requirements.txt b/requirements.txt
index a800e39..3639623 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,7 +21,7 @@ nose==1.3.7
 numpy==1.13.3
 olefile==0.44
 Pillow==4.3.0
-protobuf==3.5.1
+protobuf==3.15.0
 pyasn1==0.4.2
 pyasn1-modules==0.2.1
 pytesseract==0.2.0