diff --git a/requirements/requirements-ci.txt b/requirements/requirements-ci.txt
index 905e6fb086..4da7ec1631 100644
--- a/requirements/requirements-ci.txt
+++ b/requirements/requirements-ci.txt
@@ -490,7 +490,7 @@ prompt-toolkit==3.0.5
     # via
     #   -r requirements-dev.txt
     #   ipython
-protobuf==3.15.0
+protobuf==3.18.3
     # via
     #   -r requirements-dev.txt
     #   web3
@@ -683,7 +683,6 @@ six==1.16.0
     #   jsonschema
     #   multiaddr
     #   parsimonious
-    #   protobuf
     #   pymacaroons
     #   pynacl
     #   pyopenssl
diff --git a/requirements/requirements-dev.txt b/requirements/requirements-dev.txt
index e1c4339415..bad588febb 100644
--- a/requirements/requirements-dev.txt
+++ b/requirements/requirements-dev.txt
@@ -424,7 +424,7 @@ prometheus-client==0.8.0
     # via matrix-synapse
 prompt-toolkit==3.0.5
     # via ipython
-protobuf==3.15.0
+protobuf==3.18.3
     # via
     #   -r requirements.txt
     #   web3
@@ -582,7 +582,6 @@ six==1.16.0
     #   jsonschema
     #   multiaddr
     #   parsimonious
-    #   protobuf
     #   pymacaroons
     #   pynacl
     #   pyopenssl
diff --git a/requirements/requirements.txt b/requirements/requirements.txt
index b89330de39..178308e1a7 100644
--- a/requirements/requirements.txt
+++ b/requirements/requirements.txt
@@ -205,7 +205,7 @@ packaging==21.3
     #   marshmallow
 parsimonious==0.8.1
     # via eth-abi
-protobuf==3.15.0
+protobuf==3.18.3
     # via web3
 psutil==5.8.0
     # via
@@ -264,7 +264,6 @@ six==1.16.0
     #   jsonschema
     #   multiaddr
     #   parsimonious
-    #   protobuf
     #   pyrsistent
     #   thrift
 structlog==21.5.0