diff --git a/tsdb/fileutil/mmap.go b/tsdb/fileutil/mmap.go
index 4dbca4f97..782ff27ec 100644
--- a/tsdb/fileutil/mmap.go
+++ b/tsdb/fileutil/mmap.go
@@ -14,9 +14,8 @@
 package fileutil
 
 import (
+	"fmt"
 	"os"
-
-	"github.com/pkg/errors"
 )
 
 type MmapFile struct {
@@ -31,7 +30,7 @@ func OpenMmapFile(path string) (*MmapFile, error) {
 func OpenMmapFileWithSize(path string, size int) (mf *MmapFile, retErr error) {
 	f, err := os.Open(path)
 	if err != nil {
-		return nil, errors.Wrap(err, "try lock file")
+		return nil, fmt.Errorf("try lock file: %w", err)
 	}
 	defer func() {
 		if retErr != nil {
@@ -41,14 +40,14 @@ func OpenMmapFileWithSize(path string, size int) (mf *MmapFile, retErr error) {
 	if size <= 0 {
 		info, err := f.Stat()
 		if err != nil {
-			return nil, errors.Wrap(err, "stat")
+			return nil, fmt.Errorf("stat: %w", err)
 		}
 		size = int(info.Size())
 	}
 
 	b, err := mmap(f, size)
 	if err != nil {
-		return nil, errors.Wrapf(err, "mmap, size %d", size)
+		return nil, fmt.Errorf("mmap, size %d: %w", size, err)
 	}
 
 	return &MmapFile{f: f, b: b}, nil
diff --git a/tsdb/fileutil/preallocate_linux.go b/tsdb/fileutil/preallocate_linux.go
index ada046221..026c69b35 100644
--- a/tsdb/fileutil/preallocate_linux.go
+++ b/tsdb/fileutil/preallocate_linux.go
@@ -15,6 +15,7 @@
 package fileutil
 
 import (
+	"errors"
 	"os"
 	"syscall"
 )
@@ -23,10 +24,10 @@ func preallocExtend(f *os.File, sizeInBytes int64) error {
 	// use mode = 0 to change size
 	err := syscall.Fallocate(int(f.Fd()), 0, 0, sizeInBytes)
 	if err != nil {
-		errno, ok := err.(syscall.Errno)
+		var errno syscall.Errno
 		// not supported; fallback
 		// fallocate EINTRs frequently in some environments; fallback
-		if ok && (errno == syscall.ENOTSUP || errno == syscall.EINTR) {
+		if errors.As(err, &errno) && (errno == syscall.ENOTSUP || errno == syscall.EINTR) {
 			return preallocExtendTrunc(f, sizeInBytes)
 		}
 	}
@@ -37,9 +38,9 @@ func preallocFixed(f *os.File, sizeInBytes int64) error {
 	// use mode = 1 to keep size; see FALLOC_FL_KEEP_SIZE
 	err := syscall.Fallocate(int(f.Fd()), 1, 0, sizeInBytes)
 	if err != nil {
-		errno, ok := err.(syscall.Errno)
+		var errno syscall.Errno
 		// treat not supported as nil error
-		if ok && errno == syscall.ENOTSUP {
+		if errors.As(err, &errno) && errno == syscall.ENOTSUP {
 			return nil
 		}
 	}