diff --git a/vault/logical_system.go b/vault/logical_system.go
index 52f1c7a0b3..89ec1a379d 100644
--- a/vault/logical_system.go
+++ b/vault/logical_system.go
@@ -3,6 +3,7 @@ package vault
 import (
 	"fmt"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/hashicorp/vault/logical"
@@ -845,6 +846,14 @@ func (b *SystemBackend) handleMountTuneWrite(
 		return handleError(err)
 	}
 
+	var lock *sync.RWMutex
+	switch {
+	case strings.HasPrefix(path, "auth/"):
+		lock = &b.Core.authLock
+	default:
+		lock = &b.Core.mountsLock
+	}
+
 	// Timing configuration parameters
 	{
 		var newDefault, newMax *time.Duration
@@ -877,8 +886,9 @@ func (b *SystemBackend) handleMountTuneWrite(
 		}
 
 		if newDefault != nil || newMax != nil {
-			b.Core.mountsLock.Lock()
-			defer b.Core.mountsLock.Unlock()
+			lock.Lock()
+			defer lock.Unlock()
+
 			if err := b.tuneMountTTLs(path, &mountEntry.Config, newDefault, newMax); err != nil {
 				b.Backend.Logger().Printf("[ERR] sys: tune of path '%s' failed: %v", path, err)
 				return handleError(err)
diff --git a/vault/logical_system_helpers.go b/vault/logical_system_helpers.go
index b6d35ef76a..a3fb945794 100644
--- a/vault/logical_system_helpers.go
+++ b/vault/logical_system_helpers.go
@@ -1,8 +1,8 @@
 package vault
 
 import (
-	"errors"
 	"fmt"
+	"strings"
 	"time"
 )
 
@@ -51,6 +51,9 @@ func (b *SystemBackend) tuneMountTTLs(path string, meConfig *MountConfig, newDef
 		}
 	}
 
+	origMax := meConfig.MaxLeaseTTL
+	origDefault := meConfig.DefaultLeaseTTL
+
 	if newMax != nil {
 		meConfig.MaxLeaseTTL = *newMax
 	}
@@ -59,8 +62,17 @@ func (b *SystemBackend) tuneMountTTLs(path string, meConfig *MountConfig, newDef
 	}
 
 	// Update the mount table
-	if err := b.Core.persistMounts(b.Core.mounts); err != nil {
-		return errors.New("failed to update mount table")
+	var err error
+	switch {
+	case strings.HasPrefix(path, "auth/"):
+		err = b.Core.persistAuth(b.Core.auth)
+	default:
+		err = b.Core.persistMounts(b.Core.mounts)
+	}
+	if err != nil {
+		meConfig.MaxLeaseTTL = origMax
+		meConfig.DefaultLeaseTTL = origDefault
+		return fmt.Errorf("failed to update mount table, rolling back TTL changes")
 	}
 
 	b.Core.logger.Printf("[INFO] core: tuned '%s'", path)