diff --git a/interface.go b/interface.go
index d0834afa94..f24c9a51f6 100644
--- a/interface.go
+++ b/interface.go
@@ -119,6 +119,7 @@ type ServiceAPIClient interface {
 type SwarmAPIClient interface {
 	SwarmInit(ctx context.Context, req swarm.InitRequest) (string, error)
 	SwarmJoin(ctx context.Context, req swarm.JoinRequest) error
+	SwarmGetUnlockKey(ctx context.Context) (types.SwarmUnlockKeyResponse, error)
 	SwarmUnlock(ctx context.Context, req swarm.UnlockRequest) error
 	SwarmLeave(ctx context.Context, force bool) error
 	SwarmInspect(ctx context.Context) (swarm.Swarm, error)
diff --git a/swarm_get_unlock_key.go b/swarm_get_unlock_key.go
new file mode 100644
index 0000000000..be28d32628
--- /dev/null
+++ b/swarm_get_unlock_key.go
@@ -0,0 +1,21 @@
+package client
+
+import (
+	"encoding/json"
+
+	"github.com/docker/docker/api/types"
+	"golang.org/x/net/context"
+)
+
+// SwarmGetUnlockKey retrieves the swarm's unlock key.
+func (cli *Client) SwarmGetUnlockKey(ctx context.Context) (types.SwarmUnlockKeyResponse, error) {
+	serverResp, err := cli.get(ctx, "/swarm/unlockkey", nil, nil)
+	if err != nil {
+		return types.SwarmUnlockKeyResponse{}, err
+	}
+
+	var response types.SwarmUnlockKeyResponse
+	err = json.NewDecoder(serverResp.body).Decode(&response)
+	ensureReaderClosed(serverResp)
+	return response, err
+}