diff --git a/internal/campaign/sync.go b/internal/campaign/sync.go
index 7fbdc78..cf6ab95 100644
--- a/internal/campaign/sync.go
+++ b/internal/campaign/sync.go
@@ -217,6 +217,10 @@ func attachmentFilename(slug, relPath string, content []byte) string {
 func campaignUnchanged(existing *listmonk.Campaign, input listmonk.CampaignInput) bool {
 	return existing.Subject == input.Subject &&
 		existing.Body == input.Body &&
+		// altbody always mirrors body (see CampaignInput.payload) -- comparing
+		// it here is what catches a campaign synced before that started, whose
+		// stored altbody is still null even though its body hasn't changed.
+		existing.AltBody == input.Body &&
 		existing.FromEmail == input.FromEmail &&
 		existing.TemplateID == input.TemplateID &&
 		existing.Type == input.Type &&
diff --git a/internal/campaign/sync_test.go b/internal/campaign/sync_test.go
index 3dfdd78..0e19063 100644
--- a/internal/campaign/sync_test.go
+++ b/internal/campaign/sync_test.go
@@ -31,6 +31,7 @@ type fakeCampaign struct {
 	Status     string
 	Subject    string
 	Body       string
+	AltBody    string
 	FromEmail  string
 	TemplateID int
 	Type       string
@@ -138,7 +139,7 @@ func (c fakeCampaign) toJSON() map[string]any {
 	}
 	return map[string]any{
 		"id": c.ID, "name": c.Name, "status": c.Status, "subject": c.Subject,
-		"body": c.Body, "from_email": c.FromEmail, "template_id": c.TemplateID,
+		"body": c.Body, "altbody": c.AltBody, "from_email": c.FromEmail, "template_id": c.TemplateID,
 		"type": c.Type, "tags": c.Tags, "lists": lists, "media": media,
 	}
 }
@@ -155,7 +156,7 @@ func (f *fakeListmonk) createCampaign(w http.ResponseWriter, r *http.Request) {
 	body := decodeBody(r)
 	c := fakeCampaign{
 		ID: f.id(), Name: str(body["name"]), Status: "draft",
-		Subject: str(body["subject"]), Body: str(body["body"]),
+		Subject: str(body["subject"]), Body: str(body["body"]), AltBody: str(body["altbody"]),
 		FromEmail: str(body["from_email"]), TemplateID: toInt(body["template_id"]),
 		Type: str(body["type"]), Tags: toStrings(body["tags"]),
 		ListIDs: toInts(body["lists"]), MediaIDs: toInts(body["media"]),
@@ -171,6 +172,7 @@ func (f *fakeListmonk) updateCampaign(w http.ResponseWriter, r *http.Request) {
 		if f.campaigns[i].ID == id {
 			f.campaigns[i].Subject = str(body["subject"])
 			f.campaigns[i].Body = str(body["body"])
+			f.campaigns[i].AltBody = str(body["altbody"])
 			f.campaigns[i].FromEmail = str(body["from_email"])
 			f.campaigns[i].TemplateID = toInt(body["template_id"])
 			f.campaigns[i].Type = str(body["type"])
diff --git a/internal/listmonk/listmonk.go b/internal/listmonk/listmonk.go
index 9dae237..c4b0454 100644
--- a/internal/listmonk/listmonk.go
+++ b/internal/listmonk/listmonk.go
@@ -289,6 +289,7 @@ type Campaign struct {
 	Status     string
 	Subject    string
 	Body       string
+	AltBody    string
 	FromEmail  string
 	TemplateID int
 	Type       string
@@ -381,6 +382,7 @@ func parseCampaign(data []byte) (*Campaign, error) {
 		Status     string   `json:"status"`
 		Subject    string   `json:"subject"`
 		Body       string   `json:"body"`
+		AltBody    string   `json:"altbody"`
 		FromEmail  string   `json:"from_email"`
 		TemplateID int      `json:"template_id"`
 		Type       string   `json:"type"`
@@ -409,6 +411,7 @@ func parseCampaign(data []byte) (*Campaign, error) {
 		Status:     parsed.Status,
 		Subject:    parsed.Subject,
 		Body:       parsed.Body,
+		AltBody:    parsed.AltBody,
 		FromEmail:  parsed.FromEmail,
 		TemplateID: parsed.TemplateID,
 		Type:       parsed.Type,