diff --git a/.changeset/few-ants-share.md b/.changeset/few-ants-share.md
new file mode 100644
index 00000000..4dcf48dd
--- /dev/null
+++ b/.changeset/few-ants-share.md
@@ -0,0 +1,5 @@
+---
+"@buape/carbon": patch
+---
+
+fix: make ephemeral responses work properly
diff --git a/apps/rocko/src/commands/testing/ephemeral.ts b/apps/rocko/src/commands/testing/ephemeral.ts
new file mode 100644
index 00000000..c7a589b0
--- /dev/null
+++ b/apps/rocko/src/commands/testing/ephemeral.ts
@@ -0,0 +1,35 @@
+import {
+	Command,
+	type CommandInteraction,
+	CommandWithSubcommands
+} from "@buape/carbon"
+
+export default class EphemeralCommand extends CommandWithSubcommands {
+	name = "ephemeral"
+	description = "Ephemeral test"
+	ephemeral = true
+
+	subcommands = [new EphemeralNoDefer(), new EphemeralDefer()]
+}
+
+class EphemeralNoDefer extends Command {
+	name = "no-defer"
+	description = "Ephemeral test"
+	ephemeral = true
+	defer = false
+
+	async run(interaction: CommandInteraction): Promise<void> {
+		return interaction.reply({ content: "Ephemeral no defer" })
+	}
+}
+
+export class EphemeralDefer extends Command {
+	name = "defer"
+	description = "Ephemeral test"
+	ephemeral = true
+	defer = true
+
+	async run(interaction: CommandInteraction): Promise<void> {
+		return interaction.reply({ content: "Ephemeral defer" })
+	}
+}
diff --git a/packages/carbon/src/abstracts/BaseInteraction.ts b/packages/carbon/src/abstracts/BaseInteraction.ts
index 3cd694c1..80658603 100644
--- a/packages/carbon/src/abstracts/BaseInteraction.ts
+++ b/packages/carbon/src/abstracts/BaseInteraction.ts
@@ -3,6 +3,7 @@ import {
 	type APIInteraction,
 	InteractionResponseType,
 	type InteractionType,
+	MessageFlags,
 	type RESTPatchAPIInteractionOriginalResponseJSONBody,
 	type RESTPostAPIInteractionCallbackJSONBody,
 	type RESTPostAPIInteractionFollowupJSONBody,
@@ -154,10 +155,12 @@ export abstract class BaseInteraction<T extends APIInteraction> extends Base {
 					body: {
 						type: InteractionResponseType.ChannelMessageWithSource,
 						data: {
-							...serializePayload(data),
-							flags: options.ephemeral
-								? 64 | ("flags" in serialized ? (serialized.flags ?? 0) : 0)
-								: undefined
+							...serialized,
+							flags:
+								options.ephemeral || this.defaultEphemeral
+									? MessageFlags.Ephemeral |
+										("flags" in serialized ? (serialized.flags ?? 0) : 0)
+									: undefined
 						}
 					} as RESTPostAPIInteractionCallbackJSONBody,
 					files: options.files
@@ -171,7 +174,7 @@ export abstract class BaseInteraction<T extends APIInteraction> extends Base {
 	 * If the interaction is already deferred, this will do nothing.
 	 * @internal
 	 */
-	async defer() {
+	async defer({ ephemeral = false } = {}) {
 		if (this._deferred) return
 		this._deferred = true
 		await this.client.rest.post(
@@ -179,8 +182,13 @@ export abstract class BaseInteraction<T extends APIInteraction> extends Base {
 			{
 				body: {
 					type: InteractionResponseType.DeferredChannelMessageWithSource,
-					flags: this.defaultEphemeral ? 64 : undefined
-				} as RESTPostAPIInteractionCallbackJSONBody
+					data: {
+						flags:
+							ephemeral || this.defaultEphemeral
+								? MessageFlags.Ephemeral
+								: undefined
+					}
+				} satisfies RESTPostAPIInteractionCallbackJSONBody
 			}
 		)
 	}
@@ -198,7 +206,7 @@ export abstract class BaseInteraction<T extends APIInteraction> extends Base {
 				body: {
 					type: InteractionResponseType.Modal,
 					data: modal.serialize()
-				} as RESTPostAPIInteractionCallbackJSONBody
+				} satisfies RESTPostAPIInteractionCallbackJSONBody
 			}
 		)
 	}
@@ -214,7 +222,8 @@ export abstract class BaseInteraction<T extends APIInteraction> extends Base {
 				body: {
 					...serialized,
 					flags: options.ephemeral
-						? 64 | ("flags" in serialized ? (serialized.flags ?? 0) : 0)
+						? MessageFlags.Ephemeral |
+							("flags" in serialized ? (serialized.flags ?? 0) : 0)
 						: undefined
 				} as RESTPostAPIInteractionFollowupJSONBody,
 				files: options.files
diff --git a/packages/carbon/src/utils.ts b/packages/carbon/src/utils.ts
index 620d0d98..7f507360 100644
--- a/packages/carbon/src/utils.ts
+++ b/packages/carbon/src/utils.ts
@@ -82,12 +82,20 @@ export function concatUint8Arrays(
 	return merged
 }
 
-export const serializePayload = (payload: MessagePayload) => {
-	return typeof payload === "string"
-		? { content: payload }
-		: {
-				...payload,
-				embeds: payload.embeds?.map((embed) => embed.serialize()),
-				components: payload.components?.map((row) => row.serialize())
-			}
+export const serializePayload = (
+	payload: MessagePayload,
+	defaultEphemeral = false
+) => {
+	if (typeof payload === "string") {
+		return { content: payload, flags: defaultEphemeral ? 64 : undefined }
+	}
+	const data = {
+		...payload,
+		embeds: payload.embeds?.map((embed) => embed.serialize()),
+		components: payload.components?.map((row) => row.serialize())
+	}
+	if (defaultEphemeral) {
+		data.flags = 64
+	}
+	return data
 }