diff --git a/packages/demo-protobuf/package.json b/packages/demo-protobuf/package.json
index e9b40f98..2484419b 100644
--- a/packages/demo-protobuf/package.json
+++ b/packages/demo-protobuf/package.json
@@ -39,6 +39,6 @@
   },
   "devDependencies": {
     "@cosmjs/utils": "^0.20.0",
-    "protobufjs": "^6.9.0"
+    "protobufjs": "~6.9.0"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index a79e7f54..1b65a92c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6254,7 +6254,7 @@ proto-list@~1.2.1:
   resolved "https://registry.yarnpkg.com/proto-list/-/proto-list-1.2.4.tgz#212d5bfe1318306a420f6402b8e26ff39647a849"
   integrity sha1-IS1b/hMYMGpCD2QCuOJv85ZHqEk=
 
-protobufjs@^6.9.0:
+protobufjs@~6.9.0:
   version "6.9.0"
   resolved "https://registry.yarnpkg.com/protobufjs/-/protobufjs-6.9.0.tgz#c08b2bf636682598e6fabbf0edb0b1256ff090bd"
   integrity sha512-LlGVfEWDXoI/STstRDdZZKb/qusoAWUnmLg9R8OLSO473mBLWHowx8clbX5/+mKDEI+v7GzjoK9tRPZMMcoTrg==