diff --git a/context/context.go b/context/context.go
index 465a763..a549ba2 100644
--- a/context/context.go
+++ b/context/context.go
@@ -1,6 +1,9 @@
 package context
 
-import "sync"
+import (
+	"reflect"
+	"sync"
+)
 
 type ContextKey string
 
@@ -12,22 +15,21 @@ func NewContext(parent Context) Context {
 	c := &defaultContext{
 		Context: parent,
 	}
-	c.attributes = make(map[string]interface{})
-
+	c.attributes = make(map[interface{}]interface{})
 	return c
 }
 
 type Context interface {
 	Parent() Context
-	SetAttribute(key string, value interface{})
-	GetAttribute(key string) (value interface{})
-	RemoveAttribute(key string)
-	ContainsAttribute(key string) (exist bool)
+	SetAttribute(key interface{}, value interface{})
+	GetAttribute(key interface{}) (value interface{})
+	RemoveAttribute(key interface{})
+	ContainsAttribute(key interface{}) (exist bool)
 }
 
 type defaultContext struct {
 	Context
-	attributes map[string]interface{}
+	attributes map[interface{}]interface{}
 
 	mtx sync.RWMutex
 }
@@ -36,16 +38,23 @@ func (dc *defaultContext) Parent() Context {
 	return dc.Context
 }
 
-func (dc *defaultContext) SetAttribute(key string, value interface{}) {
+func (dc *defaultContext) SetAttribute(key interface{}, value interface{}) {
 	dc.checkInitialized()
 
+	if key == nil {
+		panic("nil key")
+	}
+	if !reflect.TypeOf(key).Comparable() {
+		panic("key is not comparable")
+	}
+
 	dc.mtx.Lock()
 	defer dc.mtx.Unlock()
 
 	dc.attributes[key] = value
 }
 
-func (dc *defaultContext) GetAttribute(key string) (value interface{}) {
+func (dc *defaultContext) GetAttribute(key interface{}) (value interface{}) {
 	dc.checkInitialized()
 
 	dc.mtx.RLock()
@@ -61,7 +70,7 @@ func (dc *defaultContext) GetAttribute(key string) (value interface{}) {
 	return dc.Context.GetAttribute(key)
 }
 
-func (dc *defaultContext) RemoveAttribute(key string) {
+func (dc *defaultContext) RemoveAttribute(key interface{}) {
 	dc.checkInitialized()
 
 	dc.mtx.Lock()
@@ -79,7 +88,7 @@ func (dc *defaultContext) RemoveAttribute(key string) {
 	dc.Context.RemoveAttribute(key)
 }
 
-func (dc *defaultContext) ContainsAttribute(key string) (exist bool) {
+func (dc *defaultContext) ContainsAttribute(key interface{}) (exist bool) {
 	dc.checkInitialized()
 
 	dc.mtx.RLock()