diff --git a/package.json b/package.json
index 58555fb..1fb9e70 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "cordis",
   "description": "AOP Framework for Modern JavaScript Applications",
-  "version": "3.5.1",
+  "version": "3.5.2",
   "sideEffects": false,
   "main": "lib/index.cjs",
   "module": "lib/index.mjs",
diff --git a/src/context.ts b/src/context.ts
index 35f83fe..1edd9bb 100644
--- a/src/context.ts
+++ b/src/context.ts
@@ -261,6 +261,7 @@ export class Context {
 
   provide(name: string, value?: any, builtin?: boolean) {
     const internal = Context.ensureInternal.call(this.root)
+    if (name in internal) return
     const key = Symbol(name)
     internal[name] = { type: 'service', key, builtin }
     this.root[key] = value
@@ -268,13 +269,13 @@ export class Context {
 
   accessor(name: string, options: Omit<Context.Internal.Accessor, 'type'>) {
     const internal = Context.ensureInternal.call(this.root)
-    internal[name] = { type: 'accessor', ...options }
+    internal[name] ||= { type: 'accessor', ...options }
   }
 
   alias(name: string, aliases: string[]) {
     const internal = Context.ensureInternal.call(this.root)
     for (const key of aliases) {
-      internal[key] = { type: 'alias', name }
+      internal[key] ||= { type: 'alias', name }
     }
   }
 
diff --git a/tests/service.spec.ts b/tests/service.spec.ts
index 4a6232b..13617c2 100644
--- a/tests/service.spec.ts
+++ b/tests/service.spec.ts
@@ -58,7 +58,8 @@ describe('Service', () => {
     root.on('internal/warning', warn)
     root.alias('bar', ['baz'])
     root.mixin('foo', ['bar'])
-    root.provide('foo', { bar: 1 })
+    root.provide('foo')
+    root.foo = { bar: 1 }
 
     // foo is a service
     expect(root.get('foo')).to.be.ok