diff --git a/requirements.txt b/requirements.txt
index ae5b535..93ee5ae 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -31,7 +31,7 @@ oauth2client==4.1.3
 olefile==0.46
 pdfminer.six==20181108
 Pillow==7.1.2
-protobuf==3.11.3
+protobuf==3.18.3
 pyasn1==0.4.8
 pyasn1-modules==0.2.8
 pycryptodome==3.9.7