diff --git a/smm4h/requirements.txt b/smm4h/requirements.txt
index 45171f1..3944f1d 100644
--- a/smm4h/requirements.txt
+++ b/smm4h/requirements.txt
@@ -74,7 +74,7 @@ pickleshare==0.7.4
 plac==0.9.6
 prometheus-client==0.7.1
 prompt-toolkit==1.0.15
-protobuf==3.11.3
+protobuf==3.18.3
 ptyprocess==0.5.2
 pycparser==2.18
 pyemd==0.5.1