diff --git a/packages/context/src/inject.ts b/packages/context/src/inject.ts
index 15638e33eff5..2a8d618b9fe1 100644
--- a/packages/context/src/inject.ts
+++ b/packages/context/src/inject.ts
@@ -39,7 +39,7 @@ export interface ResolverFunction {
   (
     ctx: Context,
     injection: Readonly<Injection>,
-    session?: ResolutionSession,
+    session: ResolutionSession,
   ): ValueOrPromise<BoundValue>;
 }
 
diff --git a/packages/context/src/resolution-session.ts b/packages/context/src/resolution-session.ts
index 39ebeaf74cc9..1003cae8b2a5 100644
--- a/packages/context/src/resolution-session.ts
+++ b/packages/context/src/resolution-session.ts
@@ -16,7 +16,7 @@ const getTargetName = DecoratorFactory.getTargetName;
  * A function to be executed with the resolution session
  */
 export type ResolutionAction = (
-  session?: ResolutionSession,
+  session: ResolutionSession,
 ) => ValueOrPromise<BoundValue>;
 
 /**