diff --git a/raft/raft.go b/raft/raft.go
index 0ac40315b..baf03ea8f 100644
--- a/raft/raft.go
+++ b/raft/raft.go
@@ -29,8 +29,6 @@ import (
 const None uint64 = 0
 const noLimit = math.MaxUint64
 
-var ErrSnapshotTemporarilyUnavailable = errors.New("snapshot is temporarily unavailable")
-
 // Possible values for StateType.
 const (
 	StateFollower StateType = iota
@@ -231,7 +229,7 @@ func newRaft(c *Config) *raft {
 	}
 	r.becomeFollower(r.Term, None)
 
-	nodesStrs := make([]string, 0)
+	var nodesStrs []string
 	for _, n := range r.nodes() {
 		nodesStrs = append(nodesStrs, fmt.Sprintf("%x", n))
 	}
diff --git a/raft/storage.go b/raft/storage.go
index f3724162c..78d192556 100644
--- a/raft/storage.go
+++ b/raft/storage.go
@@ -29,8 +29,14 @@ var ErrCompacted = errors.New("requested index is unavailable due to compaction"
 // index is older than the existing snapshot.
 var ErrSnapOutOfDate = errors.New("requested index is older than the existing snapshot")
 
+// ErrUnavailable is returned by Storage interface when the requested log entries
+// are unavailable.
 var ErrUnavailable = errors.New("requested entry at index is unavailable")
 
+// ErrSnapshotTemporarilyUnavailable is returned by the Storage interface when the required
+// snapshot is temporarily unavailable.
+var ErrSnapshotTemporarilyUnavailable = errors.New("snapshot is temporarily unavailable")
+
 // Storage is an interface that may be implemented by the application
 // to retrieve log entries from storage.
 //