diff --git a/pkg/cache/cache.go b/pkg/cache/cache.go
index 44ae5cb..041ef21 100644
--- a/pkg/cache/cache.go
+++ b/pkg/cache/cache.go
@@ -2,6 +2,6 @@ package cache
 
 type Cache interface {
 	Get(namespace string) Namespace
-	Clear(namespace string)
+	Clear(namespaces ...string)
 	List() map[string]Namespace
 }
diff --git a/pkg/cache/memorycache.go b/pkg/cache/memorycache.go
index ca8c860..3086a81 100644
--- a/pkg/cache/memorycache.go
+++ b/pkg/cache/memorycache.go
@@ -1,32 +1,43 @@
 package cache
 
-type MemoryCache map[string]MemoryNamespace
+import (
+	"sync"
+)
 
-func NewMemoryCache() MemoryCache {
-	return MemoryCache{}
+type MemoryCache struct {
+	store sync.Map
 }
 
-func (c MemoryCache) Clear(namespace string) {
-	if namespace == "" {
-		for _, value := range c {
-			value.Delete("")
-		}
-	} else {
-		c.Get(namespace).Delete("")
+func NewMemoryCache() *MemoryCache {
+	return &MemoryCache{
+		store: sync.Map{},
 	}
 }
 
-func (c MemoryCache) Get(namespace string) Namespace {
-	if _, ok := c[namespace]; !ok {
-		c[namespace] = MemoryNamespace{}
+func (c *MemoryCache) Clear(namespaces ...string) {
+	if len(namespaces) == 0 {
+		c.store.Range(func(key, value interface{}) bool {
+			namespaces = append(namespaces, key.(string))
+			return true
+		})
+	}
+	for _, namespace := range namespaces {
+		c.Get(namespace).Delete()
 	}
-	return c[namespace]
 }
 
-func (c MemoryCache) List() map[string]Namespace {
+func (c *MemoryCache) Get(namespace string) Namespace {
+	value, _ := c.store.LoadOrStore(namespace, &MemoryNamespace{
+		store: sync.Map{},
+	})
+	return value.(*MemoryNamespace)
+}
+
+func (c *MemoryCache) List() map[string]Namespace {
 	ret := map[string]Namespace{}
-	for s, namespace := range c {
-		ret[s] = namespace
-	}
+	c.store.Range(func(k, v interface{}) bool {
+		ret[k.(string)] = v.(*MemoryNamespace)
+		return true
+	})
 	return ret
 }
diff --git a/pkg/cache/memorynamespace.go b/pkg/cache/memorynamespace.go
index 2faeb02..6c615f3 100644
--- a/pkg/cache/memorynamespace.go
+++ b/pkg/cache/memorynamespace.go
@@ -1,38 +1,44 @@
 package cache
 
-import "github.com/c-bata/go-prompt"
+import (
+	"sync"
 
-type MemoryNamespace map[string]interface{}
+	"github.com/c-bata/go-prompt"
+)
 
-func (c MemoryNamespace) Delete(key string) {
-	if key == "" {
-		for key := range c {
-			delete(c, key)
-		}
+type MemoryNamespace struct {
+	store sync.Map
+}
+
+func (c *MemoryNamespace) Delete(keys ...string) {
+	if len(keys) == 0 {
+		c.store.Clear()
 	} else {
-		delete(c, key)
-	}
-}
-
-func (c MemoryNamespace) Get(key string, cb func() interface{}) interface{} {
-	if _, ok := c[key]; !ok {
-		if cb == nil {
-			return nil
+		for _, key := range keys {
+			c.store.Delete(key)
 		}
-		c[key] = cb()
 	}
-	return c[key]
 }
 
-func (c MemoryNamespace) Keys() []string {
-	keys := make([]string, 0, len(c))
-	for k := range c {
-		keys = append(keys, k)
+func (c *MemoryNamespace) Get(key string, cb func() any) any {
+	value, ok := c.store.Load(key)
+	if !ok && cb != nil {
+		value = cb()
+		c.store.Store(key, value)
 	}
+	return value
+}
+
+func (c *MemoryNamespace) Keys() []string {
+	var keys []string
+	c.store.Range(func(k, v interface{}) bool {
+		keys = append(keys, k.(string))
+		return true
+	})
 	return keys
 }
 
-func (c MemoryNamespace) GetSuggests(key string, cb func() interface{}) []prompt.Suggest {
+func (c *MemoryNamespace) GetSuggests(key string, cb func() any) []prompt.Suggest {
 	if v, ok := c.Get(key, cb).([]prompt.Suggest); ok {
 		return v
 	}
diff --git a/pkg/cache/namespace.go b/pkg/cache/namespace.go
index 9ef6373..6ffb034 100644
--- a/pkg/cache/namespace.go
+++ b/pkg/cache/namespace.go
@@ -7,6 +7,6 @@ import (
 type Namespace interface {
 	Get(key string, cb func() any) any
 	Keys() []string
-	Delete(key string)
+	Delete(keys ...string)
 	GetSuggests(key string, cb func() any) []prompt.Suggest
 }
diff --git a/pkg/command/cache.go b/pkg/command/cache.go
index 737e038..0ddf793 100644
--- a/pkg/command/cache.go
+++ b/pkg/command/cache.go
@@ -106,7 +106,7 @@ func (c *Cache) clear(ctx context.Context, r *readline.Readline) error {
 		}
 	} else {
 		c.l.Info("clearing all caches")
-		c.cache.Clear("")
+		c.cache.Clear()
 	}
 	return nil
 }