diff --git a/guide/src/feature-flags.md b/guide/src/feature-flags.md
index 6dff6b50e..75989c6d4 100644
--- a/guide/src/feature-flags.md
+++ b/guide/src/feature-flags.md
@@ -18,3 +18,9 @@ By default openraft enables no features.
    compat-07 = ["compat", "single-term-leader", "serde", "dep:or07", "compat-07-testing"]
    compat-07-testing = ["dep:tempdir", "anyhow", "dep:serde_json"]
    ```
+
+- `storage-v2`: enables `RaftLogStorage` and `RaftStateMachine` as the v2 storage
+  This is a temporary feature flag, and will be removed in the future, when v2 storage is stable.
+  This feature disables `Adapter`, which is for v1 storage to be used as v2.
+  V2 storage separates log store and state machine store so that log IO and state machine IO can be parallelized naturally. 
+  
\ No newline at end of file
diff --git a/openraft/Cargo.toml b/openraft/Cargo.toml
index c11c34df8..9123039a1 100644
--- a/openraft/Cargo.toml
+++ b/openraft/Cargo.toml
@@ -78,6 +78,11 @@ compat = []
 compat-07 = ["compat", "serde", "dep:or07", "compat-07-testing"]
 compat-07-testing = ["dep:tempfile", "anyhow", "dep:serde_json"]
 
+# Allows an application to implement a custom the v2 storage API.
+# See `openraft::storage::v2` for more details.
+# V2 API are unstable and may change in the future.
+storage-v2 = []
+
 # default = ["single-term-leader"]
 
 [package.metadata.docs.rs]
diff --git a/openraft/src/storage/mod.rs b/openraft/src/storage/mod.rs
index 2a99e5895..0c309d8a6 100644
--- a/openraft/src/storage/mod.rs
+++ b/openraft/src/storage/mod.rs
@@ -1,6 +1,6 @@
 //! The Raft storage interface and data types.
 
-pub(crate) mod adapter;
+#[cfg(not(feature = "storage-v2"))] pub(crate) mod adapter;
 mod callback;
 mod helper;
 mod log_store_ext;
@@ -10,7 +10,7 @@ mod v2;
 use std::fmt::Debug;
 use std::ops::RangeBounds;
 
-pub use adapter::Adaptor;
+#[cfg(not(feature = "storage-v2"))] pub use adapter::Adaptor;
 use async_trait::async_trait;
 pub use helper::StorageHelper;
 pub use log_store_ext::RaftLogReaderExt;
diff --git a/openraft/src/storage/v2.rs b/openraft/src/storage/v2.rs
index 7937ef234..2a640bdf3 100644
--- a/openraft/src/storage/v2.rs
+++ b/openraft/src/storage/v2.rs
@@ -23,6 +23,11 @@ pub(crate) mod sealed {
     /// Seal [`RaftLogStorage`] and [`RaftStateMachine`]. This is to prevent users from implementing
     /// them before being stable.
     pub trait Sealed {}
+
+    /// Implement non-public trait [`Sealed`] for all types so that [`RaftLogStorage`] and
+    /// [`RaftStateMachine`] can be implemented by 3rd party crates.
+    #[cfg(feature = "storage-v2")]
+    impl<T> Sealed for T {}
 }
 
 #[async_trait]