diff --git a/morphology-similarity/requirements.txt b/morphology-similarity/requirements.txt
index 83509ea..65f7009 100644
--- a/morphology-similarity/requirements.txt
+++ b/morphology-similarity/requirements.txt
@@ -86,7 +86,7 @@ plotly==4.6.0
 pprint==0.1
 prometheus-client==0.7.1
 prompt-toolkit==3.0.2
-protobuf==3.11.2
+protobuf==3.15.0
 ptyprocess==0.6.0
 pyasn1==0.4.8
 pyasn1-modules==0.2.8