diff --git a/metadata-api/requirements.txt b/metadata-api/requirements.txt
index dfd25e0..140f05e 100644
--- a/metadata-api/requirements.txt
+++ b/metadata-api/requirements.txt
@@ -38,7 +38,7 @@ pbkdf2==1.3
 pbr==3.1.1
 Pillow==8.3.2
 ply==3.10
-protobuf==3.5.2.post1
+protobuf==3.15.0
 pyasn1==0.4.2
 pyasn1-modules==0.2.1
 pycparser==2.18