diff --git a/components/script/body.rs b/components/script/body.rs
index e2d8be3ae86..fabff7397c0 100644
--- a/components/script/body.rs
+++ b/components/script/body.rs
@@ -10,7 +10,6 @@ use crate::dom::bindings::error::{Error, Fallible};
 use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::root::DomRoot;
-use crate::dom::bindings::settings_stack::AutoIncumbentScript;
 use crate::dom::bindings::str::{DOMString, USVString};
 use crate::dom::bindings::trace::RootedTraceableBox;
 use crate::dom::blob::{normalize_type_string, Blob};
@@ -137,11 +136,9 @@ impl TransmitBodyConnectHandler {
 
                 let handler = PromiseNativeHandler::new(&global, Some(promise_handler), Some(rejection_handler));
 
-                // Enter a realm, and a script,
-                // before appending the native handler.
-                let _realm = enter_realm(&*global);
-                let _ais = AutoIncumbentScript::new(&*global);
-                promise.append_native_handler(&handler);
+                let realm = enter_realm(&*global);
+                let comp = InRealm::Entered(&realm);
+                promise.append_native_handler(&handler, comp);
             }),
             &self.canceller,
         );
@@ -556,11 +553,9 @@ impl Callback for ConsumeBodyPromiseHandler {
             let handler =
                 PromiseNativeHandler::new(&global, Some(promise_handler), Some(rejection_handler));
 
-            // Enter a realm, and a script,
-            // before appending the native handler.
-            let _realm = enter_realm(&*global);
-            let _ais = AutoIncumbentScript::new(&*global);
-            read_promise.append_native_handler(&handler);
+            let realm = enter_realm(&*global);
+            let comp = InRealm::Entered(&realm);
+            read_promise.append_native_handler(&handler, comp);
         }
     }
 }
@@ -581,7 +576,12 @@ pub fn consume_body<T: BodyMixin + DomObject>(object: &T, body_type: BodyType) -
         return promise;
     }
 
-    consume_body_with_promise(object, body_type, promise.clone());
+    consume_body_with_promise(
+        object,
+        body_type,
+        promise.clone(),
+        InRealm::Already(&in_realm_proof),
+    );
 
     promise
 }
@@ -592,6 +592,7 @@ fn consume_body_with_promise<T: BodyMixin + DomObject>(
     object: &T,
     body_type: BodyType,
     promise: Rc<Promise>,
+    comp: InRealm,
 ) {
     let global = object.global();
 
@@ -637,7 +638,7 @@ fn consume_body_with_promise<T: BodyMixin + DomObject>(
         Some(rejection_handler),
     );
     // We are already in a realm and a script.
-    read_promise.append_native_handler(&handler);
+    read_promise.append_native_handler(&handler, comp);
 }
 
 // https://fetch.spec.whatwg.org/#concept-body-package-data
diff --git a/components/script/dom/promise.rs b/components/script/dom/promise.rs
index 78bbb03449c..18be293c625 100644
--- a/components/script/dom/promise.rs
+++ b/components/script/dom/promise.rs
@@ -14,6 +14,7 @@
 use crate::dom::bindings::conversions::root_from_object;
 use crate::dom::bindings::error::{Error, Fallible};
 use crate::dom::bindings::reflector::{DomObject, MutDomObject, Reflector};
+use crate::dom::bindings::settings_stack::AutoEntryScript;
 use crate::dom::bindings::utils::AsCCharPtrPtr;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promisenativehandler::PromiseNativeHandler;
@@ -242,7 +243,8 @@ impl Promise {
     }
 
     #[allow(unsafe_code)]
-    pub fn append_native_handler(&self, handler: &PromiseNativeHandler) {
+    pub fn append_native_handler(&self, handler: &PromiseNativeHandler, _comp: InRealm) {
+        let _ais = AutoEntryScript::new(&*handler.global());
         let cx = self.global().get_cx();
         rooted!(in(*cx) let resolve_func =
                 create_native_handler_function(*cx,
diff --git a/components/script/dom/testbinding.rs b/components/script/dom/testbinding.rs
index 20fe98e2516..3d48651901e 100644
--- a/components/script/dom/testbinding.rs
+++ b/components/script/dom/testbinding.rs
@@ -1003,8 +1003,8 @@ impl TestBindingMethods for TestBinding {
             resolve.map(SimpleHandler::new),
             reject.map(SimpleHandler::new),
         );
-        let p = Promise::new_in_current_realm(&global, comp);
-        p.append_native_handler(&handler);
+        let p = Promise::new_in_current_realm(&global, comp.clone());
+        p.append_native_handler(&handler, comp);
         return p;
 
         #[derive(JSTraceable, MallocSizeOf)]
diff --git a/components/script/script_module.rs b/components/script/script_module.rs
index c12b745af47..ae8d57cad98 100644
--- a/components/script/script_module.rs
+++ b/components/script/script_module.rs
@@ -321,13 +321,13 @@ impl ModuleTree {
             ))),
         );
 
-        let _realm = enter_realm(&*owner.global());
-        AlreadyInRealm::assert(&*owner.global());
-        let _ais = AutoIncumbentScript::new(&*owner.global());
+        let global = owner.global();
+        let realm = enter_realm(&*global);
+        let comp = InRealm::Entered(&realm);
 
         let promise = promise.as_ref().unwrap();
 
-        promise.append_native_handler(&handler);
+        promise.append_native_handler(&handler, comp);
     }
 }
 
@@ -723,13 +723,13 @@ impl ModuleOwner {
             ))),
         );
 
-        let realm = enter_realm(&*self.global());
+        let global = self.global();
+        let realm = enter_realm(&*global);
         let comp = InRealm::Entered(&realm);
-        let _ais = AutoIncumbentScript::new(&*self.global());
 
         let promise = Promise::new_in_current_realm(&self.global(), comp);
 
-        promise.append_native_handler(&handler);
+        promise.append_native_handler(&handler, comp);
 
         promise
     }
@@ -1362,8 +1362,7 @@ fn fetch_module_descendants_and_link(
                 unsafe {
                     let global = owner.global();
 
-                    let _realm = enter_realm(&*global);
-                    AlreadyInRealm::assert(&*global);
+                    let realm = enter_realm(&*global);
                     let _ais = AutoIncumbentScript::new(&*global);
 
                     let abv = RootedObjectVectorWrapper::new(*global.get_cx());
@@ -1402,7 +1401,8 @@ fn fetch_module_descendants_and_link(
                         ))),
                     );
 
-                    promise_all.append_native_handler(&handler);
+                    let comp = InRealm::Entered(&realm);
+                    promise_all.append_native_handler(&handler, comp);
 
                     return Some(promise_all);
                 }