diff --git a/Cargo.toml b/Cargo.toml
index c66ba1fc..e94e6a7f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ authors = ["The TiKV Project Authors"]
 repository = "https://github.com/tikv/client-rust"
 description = "The Rust language implementation of TiKV client."
 edition = "2021"
+rust-version = "1.93.0"
 
 [features]
 default = ["prometheus"]
diff --git a/examples/raw.rs b/examples/raw.rs
index cb3bdcd8..8ba5bf06 100644
--- a/examples/raw.rs
+++ b/examples/raw.rs
@@ -1,6 +1,7 @@
 // Copyright 2018 TiKV Project Authors. Licensed under Apache-2.0.
 
 #![type_length_limit = "8165158"]
+#![allow(clippy::result_large_err)]
 
 mod common;
 
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index f06204d1..0e152a80 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.84.1"
+channel = "1.93.0"
 components = ["rustfmt", "clippy"]
diff --git a/src/common/errors.rs b/src/common/errors.rs
index c48a2665..3e4a5280 100644
--- a/src/common/errors.rs
+++ b/src/common/errors.rs
@@ -68,7 +68,7 @@ pub enum Error {
     /// Wraps a `reqwest::Error`.
     /// Wraps a `grpcio::Error`.
     #[error("gRPC api error: {0}")]
-    GrpcAPI(#[from] tonic::Status),
+    GrpcAPI(tonic::Status),
     /// Wraps a `grpcio::Error`.
     #[error("url error: {0}")]
     Url(#[from] tonic::codegen::http::uri::InvalidUri),
@@ -142,6 +142,12 @@ impl From<ProtoKeyError> for Error {
     }
 }
 
+impl From<tonic::Status> for Error {
+    fn from(status: tonic::Status) -> Error {
+        Error::GrpcAPI(status)
+    }
+}
+
 /// A result holding an [`Error`](enum@Error).
 pub type Result<T> = result::Result<T, Error>;
 
@@ -157,3 +163,62 @@ macro_rules! internal_err {
         internal_err!(format!($f, $($arg),+))
     });
 }
+
+#[cfg(test)]
+mod test {
+    use tonic::Code;
+
+    use super::Error;
+    use super::ProtoKeyError;
+    use super::ProtoRegionError;
+
+    #[test]
+    fn from_tonic_status_produces_grpc_api_error() {
+        let status = tonic::Status::new(Code::Unavailable, "network unavailable");
+        let error: Error = status.clone().into();
+
+        let Error::GrpcAPI(actual_status) = error else {
+            panic!("expected Error::GrpcAPI");
+        };
+        assert_eq!(actual_status.code(), status.code());
+        assert_eq!(actual_status.message(), status.message());
+    }
+
+    #[test]
+    fn grpc_api_variant_accepts_tonic_status_payload() {
+        let error = Error::GrpcAPI(tonic::Status::new(Code::DeadlineExceeded, "timeout"));
+        let Error::GrpcAPI(status) = error else {
+            panic!("expected Error::GrpcAPI");
+        };
+        assert_eq!(status.code(), Code::DeadlineExceeded);
+        assert_eq!(status.message(), "timeout");
+    }
+
+    #[test]
+    fn from_proto_region_error_wraps_region_error() {
+        let region_error = ProtoRegionError {
+            message: "region stale".to_owned(),
+            ..Default::default()
+        };
+        let error: Error = region_error.clone().into();
+
+        let Error::RegionError(actual_region_error) = error else {
+            panic!("expected Error::RegionError");
+        };
+        assert_eq!(actual_region_error.message, region_error.message);
+    }
+
+    #[test]
+    fn from_proto_key_error_wraps_key_error() {
+        let key_error = ProtoKeyError {
+            retryable: "retry later".to_owned(),
+            ..Default::default()
+        };
+        let error: Error = key_error.clone().into();
+
+        let Error::KeyError(actual_key_error) = error else {
+            panic!("expected Error::KeyError");
+        };
+        assert_eq!(actual_key_error.retryable, key_error.retryable);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 85cd9d27..dfb61608 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -91,6 +91,7 @@
 //! ```
 
 #![allow(clippy::field_reassign_with_default)]
+#![allow(clippy::result_large_err)]
 
 pub mod backoff;
 #[doc(hidden)]
diff --git a/src/pd/retry.rs b/src/pd/retry.rs
index c9ccf1e1..5449c108 100644
--- a/src/pd/retry.rs
+++ b/src/pd/retry.rs
@@ -184,7 +184,7 @@ impl RetryClientTrait for RetryClient<Cluster> {
             cluster
                 .get_all_stores(self.timeout)
                 .await
-                .map(|resp| resp.stores.into_iter().map(Into::into).collect())
+                .map(|resp| resp.stores)
         })
     }
 
diff --git a/src/proto.rs b/src/proto.rs
index c86a819a..f0dee9af 100644
--- a/src/proto.rs
+++ b/src/proto.rs
@@ -5,7 +5,10 @@
 
 pub use protos::*;
 
+// Rust 1.93's clippy::all flags many protobuf-generated wire types as dead code.
+// Prior toolchain (1.84.1) did not fail on these generated definitions.
 #[allow(clippy::doc_lazy_continuation)]
+#[allow(dead_code)]
 mod protos {
     include!("generated/mod.rs");
 }
diff --git a/src/store/request.rs b/src/store/request.rs
index 65911dcc..2d9c29ad 100644
--- a/src/store/request.rs
+++ b/src/store/request.rs
@@ -42,7 +42,7 @@ macro_rules! impl_request {
                     .$fun(req)
                     .await
                     .map(|r| Box::new(r.into_inner()) as Box<dyn Any>)
-                    .map_err(Error::GrpcAPI)
+                    .map_err(Error::from)
             }
 
             fn label(&self) -> &'static str {
diff --git a/src/transaction/requests.rs b/src/transaction/requests.rs
index f5859ba0..db524f16 100644
--- a/src/transaction/requests.rs
+++ b/src/transaction/requests.rs
@@ -241,9 +241,8 @@ pub fn new_pessimistic_prewrite_request(
     let len = mutations.len();
     let mut req = new_prewrite_request(mutations, primary_lock, start_version, lock_ttl);
     req.for_update_ts = for_update_ts;
-    req.pessimistic_actions = iter::repeat(PessimisticAction::DoPessimisticCheck.into())
-        .take(len)
-        .collect();
+    req.pessimistic_actions =
+        iter::repeat_n(PessimisticAction::DoPessimisticCheck.into(), len).collect();
     req
 }
 
@@ -343,7 +342,7 @@ impl Shardable for kvrpcpb::CommitRequest {
     }
 
     fn apply_shard(&mut self, shard: Self::Shard) {
-        self.keys = shard.into_iter().map(Into::into).collect();
+        self.keys = shard;
     }
 
     fn apply_store(&mut self, store: &RegionStore) -> Result<()> {
@@ -570,7 +569,7 @@ impl Merge<kvrpcpb::ScanLockResponse> for Collect {
     fn merge(&self, input: Vec<Result<kvrpcpb::ScanLockResponse>>) -> Result<Self::Out> {
         input
             .into_iter()
-            .flat_map_ok(|mut resp| resp.take_locks().into_iter().map(Into::into))
+            .flat_map_ok(|mut resp| resp.take_locks().into_iter())
             .collect()
     }
 }
diff --git a/src/transaction/transaction.rs b/src/transaction/transaction.rs
index ed8eb911..8edb0b4f 100644
--- a/src/transaction/transaction.rs
+++ b/src/transaction/transaction.rs
@@ -283,9 +283,7 @@ impl<PdC: PdClient> Transaction<PdC> {
                     .retry_multi_region(retry_options.region_backoff)
                     .merge(Collect)
                     .plan();
-                plan.execute()
-                    .await
-                    .map(|r| r.into_iter().map(Into::into).collect())
+                plan.execute().await.map(|r| r.into_iter().collect())
             })
             .await
             .map(move |pairs| pairs.map(move |pair| pair.truncate_keyspace(keyspace)))
@@ -806,9 +804,7 @@ impl<PdC: PdClient> Transaction<PdC> {
                         .retry_multi_region(retry_options.region_backoff)
                         .merge(Collect)
                         .plan();
-                    plan.execute()
-                        .await
-                        .map(|r| r.into_iter().map(Into::into).collect())
+                    plan.execute().await.map(|r| r.into_iter().collect())
                 },
             )
             .await
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 10dc4d3f..3c37c2c4 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -861,7 +861,7 @@ async fn raw_write_million() -> Result<()> {
     // test batch_scan
     for batch_num in 1..4 {
         let _ = client
-            .batch_scan(iter::repeat(vec![]..).take(batch_num), limit)
+            .batch_scan(iter::repeat_n(vec![].., batch_num), limit)
             .await?;
         // FIXME: `each_limit` parameter does no work as expected. It limits the
         // entries on each region of each rangqe, instead of each range.