diff --git a/core/api.txt b/core/api.txt
index d4592bab4d..4ef46ecc15 100644
--- a/core/api.txt
+++ b/core/api.txt
@@ -613,10 +613,10 @@ ion-loading-controller,method,dismiss,dismiss(data?: any, role?: string | undefi
 ion-loading-controller,method,getTop,getTop() => Promise<HTMLIonLoadingElement | undefined>
 
 ion-menu,shadow
-ion-menu,prop,contentId,string | undefined,undefined,false,false
+ion-menu,prop,contentId,string | undefined,undefined,false,true
 ion-menu,prop,disabled,boolean,false,false,false
 ion-menu,prop,maxEdgeStart,number,50,false,false
-ion-menu,prop,menuId,string | undefined,undefined,false,false
+ion-menu,prop,menuId,string | undefined,undefined,false,true
 ion-menu,prop,side,"end" | "start",'start',false,true
 ion-menu,prop,swipeGesture,boolean,true,false,false
 ion-menu,prop,type,string | undefined,undefined,false,false
@@ -1116,7 +1116,7 @@ ion-spinner,prop,paused,boolean,false,false,false
 ion-spinner,css-prop,--color
 
 ion-split-pane,shadow
-ion-split-pane,prop,contentId,string | undefined,undefined,false,false
+ion-split-pane,prop,contentId,string | undefined,undefined,false,true
 ion-split-pane,prop,disabled,boolean,false,false,false
 ion-split-pane,prop,when,boolean | string,QUERY['lg'],false,false
 ion-split-pane,event,ionSplitPaneVisible,{ visible: boolean; },true
diff --git a/core/src/components/menu/menu.tsx b/core/src/components/menu/menu.tsx
index 458eab9f75..1f3ead2df0 100644
--- a/core/src/components/menu/menu.tsx
+++ b/core/src/components/menu/menu.tsx
@@ -49,12 +49,12 @@ export class Menu implements ComponentInterface, MenuI {
   /**
    * The content's id the menu should use.
    */
-  @Prop() contentId?: string;
+  @Prop({ reflectToAttr: true }) contentId?: string;
 
   /**
    * An id for the menu.
    */
-  @Prop() menuId?: string;
+  @Prop({ reflectToAttr: true }) menuId?: string;
 
   /**
    * The display type of the menu.
diff --git a/core/src/components/split-pane/split-pane.tsx b/core/src/components/split-pane/split-pane.tsx
index 6e638eb387..a31ac2fbd7 100644
--- a/core/src/components/split-pane/split-pane.tsx
+++ b/core/src/components/split-pane/split-pane.tsx
@@ -31,7 +31,7 @@ export class SplitPane implements ComponentInterface {
   /**
    * The content `id` of the split-pane's main content.
    */
-  @Prop() contentId?: string;
+  @Prop({ reflectToAttr: true }) contentId?: string;
 
   /**
    * If `true`, the split pane will be hidden.