diff --git a/src/storage/ReturnCode.h b/src/storage/ReturnCode.h
index db0bda7f16..2ddbd6ac25 100644
--- a/src/storage/ReturnCode.h
+++ b/src/storage/ReturnCode.h
@@ -14,7 +14,7 @@ namespace storage {
  * A collection of EnumValPtrs for the default set of result codes in the storage framework.
  * should be kept up-to-date with the Storage::ReturnCodes script-level enum.
  */
-class ReturnCode {
+class ReturnCode final {
 public:
     static void Initialize();
     static void Cleanup();
diff --git a/src/storage/backend/redis/Plugin.cc b/src/storage/backend/redis/Plugin.cc
index a94707ca45..aa94f80294 100644
--- a/src/storage/backend/redis/Plugin.cc
+++ b/src/storage/backend/redis/Plugin.cc
@@ -7,7 +7,7 @@
 
 namespace zeek::storage::backend::redis {
 
-class Plugin : public plugin::Plugin {
+class Plugin final : public plugin::Plugin {
 public:
     plugin::Configuration Configure() override {
         AddComponent(new storage::BackendComponent("REDIS", backend::redis::Redis::Instantiate));
diff --git a/src/storage/backend/redis/Redis.h b/src/storage/backend/redis/Redis.h
index 2654ef6c9c..336bcb69de 100644
--- a/src/storage/backend/redis/Redis.h
+++ b/src/storage/backend/redis/Redis.h
@@ -13,7 +13,7 @@ struct redisReply;
 struct redisPollEvents;
 
 namespace zeek::storage::backend::redis {
-class Redis : public Backend, public iosource::IOSource {
+class Redis final : public Backend, public iosource::IOSource {
 public:
     Redis() : Backend(SupportedModes::ASYNC, "REDIS"), IOSource(true) {}
     ~Redis() override = default;
diff --git a/src/storage/backend/sqlite/Plugin.cc b/src/storage/backend/sqlite/Plugin.cc
index 8498e747d8..c6ba89df94 100644
--- a/src/storage/backend/sqlite/Plugin.cc
+++ b/src/storage/backend/sqlite/Plugin.cc
@@ -7,7 +7,7 @@
 
 namespace zeek::storage::backend::sqlite {
 
-class Plugin : public plugin::Plugin {
+class Plugin final : public plugin::Plugin {
 public:
     plugin::Configuration Configure() override {
         AddComponent(new storage::BackendComponent("SQLITE", backend::sqlite::SQLite::Instantiate));
diff --git a/src/storage/backend/sqlite/SQLite.h b/src/storage/backend/sqlite/SQLite.h
index 5a35651fde..6f011611b4 100644
--- a/src/storage/backend/sqlite/SQLite.h
+++ b/src/storage/backend/sqlite/SQLite.h
@@ -10,7 +10,7 @@ struct sqlite3_stmt;
 
 namespace zeek::storage::backend::sqlite {
 
-class SQLite : public Backend {
+class SQLite final : public Backend {
 public:
     SQLite() : Backend(SupportedModes::SYNC, "SQLITE") {}
     ~SQLite() override = default;