diff --git a/packages/builders/__tests__/types.test.ts b/packages/builders/__tests__/types.test.ts
new file mode 100644
index 000000000..dfd6abef3
--- /dev/null
+++ b/packages/builders/__tests__/types.test.ts
@@ -0,0 +1,17 @@
+import { expectTypeOf } from 'vitest';
+import { SlashCommandBuilder, SlashCommandStringOption, SlashCommandSubcommandBuilder } from '../src/index.js';
+
+const getBuilder = () => new SlashCommandBuilder();
+const getStringOption = () => new SlashCommandStringOption().setName('owo').setDescription('Testing 123');
+const getSubcommand = () => new SlashCommandSubcommandBuilder().setName('owo').setDescription('Testing 123');
+
+type BuilderPropsOnly<Type = SlashCommandBuilder> = Pick<
+	Type,
+	keyof {
+		[Key in keyof Type as Type[Key] extends (...args: any) => any ? never : Key]: any;
+	}
+>;
+
+expectTypeOf(getBuilder().addStringOption(getStringOption())).toMatchTypeOf<BuilderPropsOnly>();
+
+expectTypeOf(getBuilder().addSubcommand(getSubcommand())).toMatchTypeOf<BuilderPropsOnly>();
diff --git a/packages/builders/src/interactions/slashCommands/mixins/SharedSlashCommand.ts b/packages/builders/src/interactions/slashCommands/mixins/SharedSlashCommand.ts
index 4d321073c..9e178f82f 100644
--- a/packages/builders/src/interactions/slashCommands/mixins/SharedSlashCommand.ts
+++ b/packages/builders/src/interactions/slashCommands/mixins/SharedSlashCommand.ts
@@ -27,6 +27,17 @@ export class SharedSlashCommand {
 
 	public readonly options: ToAPIApplicationCommandOptions[] = [];
 
+	/**
+	 * @deprecated Use {@link SharedSlashCommand.setDefaultMemberPermissions} or {@link SharedSlashCommand.setDMPermission} instead.
+	 */
+	public readonly default_permission: boolean | undefined = undefined;
+
+	public readonly default_member_permissions: Permissions | null | undefined = undefined;
+
+	public readonly dm_permission: boolean | undefined = undefined;
+
+	public readonly nsfw: boolean | undefined = undefined;
+
 	/**
 	 * Sets whether the command is enabled by default when the application is added to a guild.
 	 *
diff --git a/vitest.config.ts b/vitest.config.ts
index c6e4f62c4..60e469dda 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -4,6 +4,10 @@ export default defineConfig({
 	test: {
 		exclude: ['**/node_modules', '**/dist', '.idea', '.git', '.cache'],
 		passWithNoTests: true,
+        typecheck: {
+            enabled: true,
+            include: ["**/__tests__/types.test.ts"]
+        },
 		coverage: {
 			enabled: true,
 			all: true,