diff --git a/packages/components/CHANGELOG.md b/packages/components/CHANGELOG.md
index eb158bcd5111a9..4f8f6400bc544f 100644
--- a/packages/components/CHANGELOG.md
+++ b/packages/components/CHANGELOG.md
@@ -11,6 +11,7 @@
 -   `ToolsPanel`: atomic one-step state update when (un)registering panels ([#65564](https://github.com/WordPress/gutenberg/pull/65564)).
 -   `Navigator`: fix `isInitial` logic ([#65527](https://github.com/WordPress/gutenberg/pull/65527)).
 -   `ToggleGroupControl`: Fix arrow key navigation in RTL ([#65735](https://github.com/WordPress/gutenberg/pull/65735)).
+-   `Composite`: fix legacy support for the store prop ([#65821](https://github.com/WordPress/gutenberg/pull/65821)).
 
 ## 28.8.0 (2024-09-19)
 
diff --git a/packages/components/src/composite/group-label.tsx b/packages/components/src/composite/group-label.tsx
index 17070dbb86bf81..7e3c6ffdc7759c 100644
--- a/packages/components/src/composite/group-label.tsx
+++ b/packages/components/src/composite/group-label.tsx
@@ -20,11 +20,13 @@ export const CompositeGroupLabel = forwardRef<
 	WordPressComponentProps< CompositeGroupLabelProps, 'div', false >
 >( function CompositeGroupLabel( props, ref ) {
 	const context = useCompositeContext();
+
+	// @ts-expect-error The store prop is undocumented and only used by the
+	// legacy compat layer. The `store` prop is documented, but its type is
+	// obfuscated to discourage its use outside of the component's internals.
+	const store = ( props.store ?? context.store ) as Ariakit.CompositeStore;
+
 	return (
-		<Ariakit.CompositeGroupLabel
-			store={ context.store as Ariakit.CompositeStore }
-			{ ...props }
-			ref={ ref }
-		/>
+		<Ariakit.CompositeGroupLabel store={ store } { ...props } ref={ ref } />
 	);
 } );
diff --git a/packages/components/src/composite/group.tsx b/packages/components/src/composite/group.tsx
index ae21ca6f11dd92..bcfb47e684613d 100644
--- a/packages/components/src/composite/group.tsx
+++ b/packages/components/src/composite/group.tsx
@@ -20,11 +20,11 @@ export const CompositeGroup = forwardRef<
 	WordPressComponentProps< CompositeGroupProps, 'div', false >
 >( function CompositeGroup( props, ref ) {
 	const context = useCompositeContext();
-	return (
-		<Ariakit.CompositeGroup
-			store={ context.store as Ariakit.CompositeStore }
-			{ ...props }
-			ref={ ref }
-		/>
-	);
+
+	// @ts-expect-error The store prop is undocumented and only used by the
+	// legacy compat layer. The `store` prop is documented, but its type is
+	// obfuscated to discourage its use outside of the component's internals.
+	const store = ( props.store ?? context.store ) as Ariakit.CompositeStore;
+
+	return <Ariakit.CompositeGroup store={ store } { ...props } ref={ ref } />;
 } );
diff --git a/packages/components/src/composite/hover.tsx b/packages/components/src/composite/hover.tsx
index ca0bd9d8f6aa12..1507a1879cc19f 100644
--- a/packages/components/src/composite/hover.tsx
+++ b/packages/components/src/composite/hover.tsx
@@ -20,11 +20,11 @@ export const CompositeHover = forwardRef<
 	WordPressComponentProps< CompositeHoverProps, 'div', false >
 >( function CompositeHover( props, ref ) {
 	const context = useCompositeContext();
-	return (
-		<Ariakit.CompositeHover
-			store={ context.store as Ariakit.CompositeStore }
-			{ ...props }
-			ref={ ref }
-		/>
-	);
+
+	// @ts-expect-error The store prop is undocumented and only used by the
+	// legacy compat layer. The `store` prop is documented, but its type is
+	// obfuscated to discourage its use outside of the component's internals.
+	const store = ( props.store ?? context.store ) as Ariakit.CompositeStore;
+
+	return <Ariakit.CompositeGroup store={ store } { ...props } ref={ ref } />;
 } );
diff --git a/packages/components/src/composite/index.tsx b/packages/components/src/composite/index.tsx
index e9e97072261fbf..8eb562f5bdab38 100644
--- a/packages/components/src/composite/index.tsx
+++ b/packages/components/src/composite/index.tsx
@@ -73,7 +73,10 @@ export const Composite = Object.assign(
 		},
 		ref
 	) {
-		const store = Ariakit.useCompositeStore( {
+		// @ts-expect-error The store prop is undocumented and only used by the
+		// legacy compat layer.
+		const storeProp = props.store as Ariakit.CompositeStore;
+		const internalStore = Ariakit.useCompositeStore( {
 			activeId,
 			defaultActiveId,
 			setActiveId,
@@ -85,6 +88,8 @@ export const Composite = Object.assign(
 			rtl,
 		} );
 
+		const store = storeProp ?? internalStore;
+
 		const contextValue = useMemo(
 			() => ( {
 				store,
diff --git a/packages/components/src/composite/item.tsx b/packages/components/src/composite/item.tsx
index 6d75b90f0baaaa..4a02f76039a5cf 100644
--- a/packages/components/src/composite/item.tsx
+++ b/packages/components/src/composite/item.tsx
@@ -20,11 +20,11 @@ export const CompositeItem = forwardRef<
 	WordPressComponentProps< CompositeItemProps, 'button', false >
 >( function CompositeItem( props, ref ) {
 	const context = useCompositeContext();
-	return (
-		<Ariakit.CompositeItem
-			store={ context.store as Ariakit.CompositeStore }
-			{ ...props }
-			ref={ ref }
-		/>
-	);
+
+	// @ts-expect-error The store prop is undocumented and only used by the
+	// legacy compat layer. The `store` prop is documented, but its type is
+	// obfuscated to discourage its use outside of the component's internals.
+	const store = ( props.store ?? context.store ) as Ariakit.CompositeStore;
+
+	return <Ariakit.CompositeItem store={ store } { ...props } ref={ ref } />;
 } );
diff --git a/packages/components/src/composite/row.tsx b/packages/components/src/composite/row.tsx
index a082af03ad6785..1a88da557785e9 100644
--- a/packages/components/src/composite/row.tsx
+++ b/packages/components/src/composite/row.tsx
@@ -20,11 +20,11 @@ export const CompositeRow = forwardRef<
 	WordPressComponentProps< CompositeRowProps, 'div', false >
 >( function CompositeRow( props, ref ) {
 	const context = useCompositeContext();
-	return (
-		<Ariakit.CompositeRow
-			store={ context.store as Ariakit.CompositeStore }
-			{ ...props }
-			ref={ ref }
-		/>
-	);
+
+	// @ts-expect-error The store prop is undocumented and only used by the
+	// legacy compat layer. The `store` prop is documented, but its type is
+	// obfuscated to discourage its use outside of the component's internals.
+	const store = ( props.store ?? context.store ) as Ariakit.CompositeStore;
+
+	return <Ariakit.CompositeRow store={ store } { ...props } ref={ ref } />;
 } );
diff --git a/packages/components/src/composite/typeahead.tsx b/packages/components/src/composite/typeahead.tsx
index 771d58bcb6c25c..519c59ea374e5d 100644
--- a/packages/components/src/composite/typeahead.tsx
+++ b/packages/components/src/composite/typeahead.tsx
@@ -20,11 +20,11 @@ export const CompositeTypeahead = forwardRef<
 	WordPressComponentProps< CompositeTypeaheadProps, 'div', false >
 >( function CompositeTypeahead( props, ref ) {
 	const context = useCompositeContext();
-	return (
-		<Ariakit.CompositeTypeahead
-			store={ context.store as Ariakit.CompositeStore }
-			{ ...props }
-			ref={ ref }
-		/>
-	);
+
+	// @ts-expect-error The store prop is undocumented and only used by the
+	// legacy compat layer. The `store` prop is documented, but its type is
+	// obfuscated to discourage its use outside of the component's internals.
+	const store = ( props.store ?? context.store ) as Ariakit.CompositeStore;
+
+	return <Ariakit.CompositeRow store={ store } { ...props } ref={ ref } />;
 } );