diff --git a/packages/runtime-core/src/apiSetupHelpers.ts b/packages/runtime-core/src/apiSetupHelpers.ts
index fc1866af958..02ca5d53e23 100644
--- a/packages/runtime-core/src/apiSetupHelpers.ts
+++ b/packages/runtime-core/src/apiSetupHelpers.ts
@@ -131,6 +131,7 @@ type InferDefaults<T> = {
 }
 
 type InferDefault<P, T> = T extends
+  | null
   | number
   | string
   | boolean