diff --git a/.changeset/lovely-phones-retire.md b/.changeset/lovely-phones-retire.md
new file mode 100644
index 000000000..d69cac6b1
--- /dev/null
+++ b/.changeset/lovely-phones-retire.md
@@ -0,0 +1,5 @@
+---
+"bits-ui": patch
+---
+
+fix: Update `Builder` type to support all Melt UI builders
diff --git a/src/lib/bits/calendar/components/calendar-date.svelte b/src/lib/bits/calendar/components/calendar-date.svelte
index 48d3b22ed..a03578171 100644
--- a/src/lib/bits/calendar/components/calendar-date.svelte
+++ b/src/lib/bits/calendar/components/calendar-date.svelte
@@ -18,6 +18,7 @@
 	const attrs = getAttrs("date");
 
 	$: builder = $cell(date, month);
+
 	$: Object.assign(builder, attrs);
 	const dispatch = createDispatcher();
 
diff --git a/src/lib/helpers/builders.ts b/src/lib/helpers/builders.ts
index 060ad96f2..3e69dee78 100644
--- a/src/lib/helpers/builders.ts
+++ b/src/lib/helpers/builders.ts
@@ -1,13 +1,16 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
 import type { Action, ActionReturn } from "svelte/action";
 
-export type Builder = {
-	[x: PropertyKey]: unknown;
-	// eslint-disable-next-line @typescript-eslint/no-explicit-any
-	action: Action<HTMLElement, any, any>;
+export type Builder<
+	Element = any,
+	Param = any,
+	Attributes extends Record<string, any> = Record<string, any>
+> = Record<string, any> & {
+	action: Action<Element, Param, Attributes>;
 };
 
 type BuilderActionsParams = {
-	builders: Builder[];
+	builders: Builder<any, any, any>[];
 };
 
 type BuilderActionsReturn = {
@@ -36,7 +39,7 @@ export function builderActions(
 	};
 }
 
-export function getAttrs(builders: Builder[]) {
+export function getAttrs(builders: Builder<any, any, any>[]) {
 	const attrs: Record<string, unknown | undefined> = {};
 	builders.forEach((builder) => {
 		Object.keys(builder).forEach((key) => {