diff --git a/src/kv_client/mod.rs b/src/kv_client/mod.rs
index eca1b07..959d93c 100644
--- a/src/kv_client/mod.rs
+++ b/src/kv_client/mod.rs
@@ -86,19 +86,13 @@ where
     Compat01As03<RpcFuture>: Future<Output = std::result::Result<Resp, ::grpcio::Error>>,
     Resp: HasError + Sized + Clone + Send + 'static,
 {
+    let res = match fut {
+        Ok(f) => Compat01As03::new(f).await,
+        Err(e) => Err(e),
+    };
+
     let context = tikv_stats(request_name);
-
-    let fut = match fut {
-        Err(e) => return context.done(Err(ErrorKind::Grpc(e).into())),
-        Ok(f) => f,
-    };
-
-    let res = match Compat01As03::new(fut).await {
-        Err(e) => Err(ErrorKind::Grpc(e).into()),
-        Ok(r) => Ok(r),
-    };
-
-    context.done(res)
+    context.done(res.map_err(|e| ErrorKind::Grpc(e).into()))
 }
 
 #[derive(new)]
diff --git a/src/raw/client.rs b/src/raw/client.rs
index acfd9e7..41c9994 100644
--- a/src/raw/client.rs
+++ b/src/raw/client.rs
@@ -6,8 +6,6 @@ use crate::{
     Result, Value,
 };
 
-use futures::future::Either;
-use futures::prelude::future;
 use std::{sync::Arc, u32};
 
 const MAX_RAW_KV_SCAN_LIMIT: u32 = 10240;
@@ -249,19 +247,13 @@ impl Client {
     /// # });
     /// ```
     pub async fn scan(&self, range: impl Into<BoundRange>, limit: u32) -> Result<Vec<KvPair>> {
-        let request = if limit > MAX_RAW_KV_SCAN_LIMIT {
-            Either::Right(future::err(Error::max_scan_limit_exceeded(
-                limit,
-                MAX_RAW_KV_SCAN_LIMIT,
-            )))
-        } else {
-            Either::Left(
-                requests::new_raw_scan_request(range, limit, self.key_only, self.cf.clone())
-                    .execute(self.rpc.clone()),
-            )
-        };
+        if limit > MAX_RAW_KV_SCAN_LIMIT {
+            return Err(Error::max_scan_limit_exceeded(limit, MAX_RAW_KV_SCAN_LIMIT));
+        }
 
-        request.await
+        requests::new_raw_scan_request(range, limit, self.key_only, self.cf.clone())
+            .execute(self.rpc.clone())
+            .await
     }
 
     /// Create a new 'batch scan' request.
@@ -285,23 +277,15 @@ impl Client {
         ranges: impl IntoIterator<Item = impl Into<BoundRange>>,
         each_limit: u32,
     ) -> Result<Vec<KvPair>> {
-        let request = if each_limit > MAX_RAW_KV_SCAN_LIMIT {
-            Either::Right(future::err(Error::max_scan_limit_exceeded(
+        if each_limit > MAX_RAW_KV_SCAN_LIMIT {
+            return Err(Error::max_scan_limit_exceeded(
                 each_limit,
                 MAX_RAW_KV_SCAN_LIMIT,
-            )))
-        } else {
-            Either::Left(
-                requests::new_raw_batch_scan_request(
-                    ranges,
-                    each_limit,
-                    self.key_only,
-                    self.cf.clone(),
-                )
-                .execute(self.rpc.clone()),
-            )
-        };
+            ));
+        }
 
-        request.await
+        requests::new_raw_batch_scan_request(ranges, each_limit, self.key_only, self.cf.clone())
+            .execute(self.rpc.clone())
+            .await
     }
 }