diff --git a/entity_linkage/typing/knet/requirements.txt b/entity_linkage/typing/knet/requirements.txt
index 36e75e01..7d1af83f 100644
--- a/entity_linkage/typing/knet/requirements.txt
+++ b/entity_linkage/typing/knet/requirements.txt
@@ -30,7 +30,7 @@ pexpect==4.7.0
 pickleshare==0.7.5
 prometheus-client==0.6.0
 prompt-toolkit==2.0.9
-protobuf==3.7.1
+protobuf==3.15.0
 ptyprocess==0.6.0
 Pygments==2.3.1
 pyrsistent==0.14.11