diff --git a/libnetwork/internal/kvstore/boltdb/boltdb.go b/libnetwork/internal/kvstore/boltdb/boltdb.go
index d79c6155c9..8b2c05140e 100644
--- a/libnetwork/internal/kvstore/boltdb/boltdb.go
+++ b/libnetwork/internal/kvstore/boltdb/boltdb.go
@@ -3,6 +3,8 @@ package boltdb
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
 	"sync"
@@ -34,9 +36,20 @@ func New(path, bucket string) (store.Store, error) {
 	}
 
 	db, err := bolt.Open(path, filePerm, &bolt.Options{
-		Timeout: time.Minute,
+		// The bbolt package opens the underlying db file and then issues an
+		// exclusive flock to ensures that it can safely write to the db. If
+		// it fails, it'll re-issue flocks every few ms until Timeout is
+		// reached.
+		// This nanosecond timeout bypasses that retry loop and make sure the
+		// bbolt package returns an ErrTimeout straight away. That way, the
+		// daemon, and unit tests, will fail fast and loudly instead of
+		// silently introducing delays.
+		Timeout: time.Nanosecond,
 	})
 	if err != nil {
+		if errors.Is(err, bolt.ErrTimeout) {
+			return nil, fmt.Errorf("boltdb file %s is already open", path)
+		}
 		return nil, err
 	}