diff --git a/Cargo.toml b/Cargo.toml
index 8d6cd57d..c66ba1fc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,6 @@ prometheus = ["prometheus/push", "prometheus/process"]
 # Enable integration tests with a running TiKV and PD instance.
 # Use $PD_ADDRS, comma separated, to set the addresses the tests use.
 integration-tests = []
-apiv2-no-prefix = []
 
 [lib]
 name = "tikv_client"
diff --git a/Makefile b/Makefile
index 6e22ead3..ef3fd397 100644
--- a/Makefile
+++ b/Makefile
@@ -5,11 +5,11 @@ export RUSTFLAGS=-Dwarnings
 export PD_ADDRS     ?= 127.0.0.1:2379
 export MULTI_REGION ?= 1
 
-ALL_FEATURES := integration-tests apiv2-no-prefix
+ALL_FEATURES := integration-tests
 
 NEXTEST_ARGS := --config-file $(shell pwd)/config/nextest.toml
 
-INTEGRATION_TEST_ARGS := --features "integration-tests apiv2-no-prefix" --test-threads 1
+INTEGRATION_TEST_ARGS := --features "integration-tests" --test-threads 1
 
 RUN_INTEGRATION_TEST := cargo nextest run ${NEXTEST_ARGS} --all ${INTEGRATION_TEST_ARGS}
 
diff --git a/README.md b/README.md
index 3841cf63..7e5e6d9a 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ The TiKV client is a Rust library (crate). To use this crate in your project, ad
 
 ```toml
 [dependencies]
-tikv-client = "0.3"
+tikv-client = "0.4"
 ```
 
 ### Prerequisites
diff --git a/src/request/keyspace.rs b/src/request/keyspace.rs
index 94fd5f76..35ad4e64 100644
--- a/src/request/keyspace.rs
+++ b/src/request/keyspace.rs
@@ -13,6 +13,7 @@ pub const TXN_KEY_PREFIX: u8 = b'x';
 pub const KEYSPACE_PREFIX_LEN: usize = 4;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[non_exhaustive]
 pub enum Keyspace {
     Disable,
     Enable {
@@ -23,7 +24,6 @@ pub enum Keyspace {
     /// This mode is intended for **server-side embedding** use cases (e.g. embedding this client in
     /// `tikv-server`) where keys are already in API V2 "logical key bytes" form and must be passed
     /// through unchanged.
-    #[cfg(feature = "apiv2-no-prefix")]
     ApiV2NoPrefix,
 }
 
@@ -38,7 +38,6 @@ impl Keyspace {
         match self {
             Keyspace::Disable => kvrpcpb::ApiVersion::V1,
             Keyspace::Enable { .. } => kvrpcpb::ApiVersion::V2,
-            #[cfg(feature = "apiv2-no-prefix")]
             Keyspace::ApiV2NoPrefix => kvrpcpb::ApiVersion::V2,
         }
     }
@@ -293,7 +292,6 @@ mod tests {
         assert_eq!(key.truncate_keyspace(keyspace), expected_key);
     }
 
-    #[cfg(feature = "apiv2-no-prefix")]
     #[test]
     fn test_apiv2_no_prefix_api_version() {
         assert_eq!(
@@ -302,7 +300,6 @@ mod tests {
         );
     }
 
-    #[cfg(feature = "apiv2-no-prefix")]
     #[test]
     fn test_apiv2_no_prefix_encode_is_noop() {
         let keyspace = Keyspace::ApiV2NoPrefix;
@@ -325,7 +322,6 @@ mod tests {
         );
     }
 
-    #[cfg(feature = "apiv2-no-prefix")]
     #[test]
     fn test_apiv2_no_prefix_truncate_is_noop() {
         let keyspace = Keyspace::ApiV2NoPrefix;
diff --git a/src/transaction/client.rs b/src/transaction/client.rs
index 22873b0c..e28d452a 100644
--- a/src/transaction/client.rs
+++ b/src/transaction/client.rs
@@ -125,7 +125,6 @@ impl Client {
     /// keyspace/key-mode prefix, with a custom configuration.
     ///
     /// This is intended for **server-side embedding** use cases. `config.keyspace` must be unset.
-    #[cfg(feature = "apiv2-no-prefix")]
     pub async fn new_with_config_api_v2_no_prefix<S: Into<String>>(
         pd_endpoints: Vec<S>,
         config: Config,