diff --git a/src/lib/errors.ts b/src/lib/errors.ts
index a231558..7b646ae 100644
--- a/src/lib/errors.ts
+++ b/src/lib/errors.ts
@@ -71,6 +71,11 @@ const errorsList = [
 		message: 'Cannot cancel: share is not pending or downloading',
 		status: 409,
 	},
+	{
+		code: 'MAP_SHARE_CANCELED',
+		message: 'Map share has been canceled by the sender',
+		status: 409,
+	},
 	{
 		code: 'DECLINE_SHARE_NOT_PENDING',
 		message: 'Cannot decline: share is not pending',
diff --git a/src/lib/map-share.ts b/src/lib/map-share.ts
index 2178706..ba64627 100644
--- a/src/lib/map-share.ts
+++ b/src/lib/map-share.ts
@@ -78,6 +78,9 @@ export class MapShare extends TypedEventTarget<
 	decline(
 		reason: Extract<MapShareStateUpdate, { status: 'declined' }>['reason'],
 	) {
+		if (this.#state.status === 'canceled') {
+			throw new errors.MAP_SHARE_CANCELED()
+		}
 		if (this.#state.status !== 'pending') {
 			throw new errors.DECLINE_SHARE_NOT_PENDING(
 				`Cannot decline: share status is '${this.#state.status}'`,
diff --git a/test/map-shares.test.ts b/test/map-shares.test.ts
index 8e49745..bc37579 100644
--- a/test/map-shares.test.ts
+++ b/test/map-shares.test.ts
@@ -589,7 +589,7 @@ describe('Map Shares and Downloads', () => {
 				expect(events.at(-1)).toHaveProperty('error.message')
 			})
 
-			it('should reject decline on non-pending share', async (t) => {
+			it('should return MAP_SHARE_CANCELED when declining a canceled share', async (t) => {
 				const { createShare, sender, receiver } = await startServers(t)
 
 				const share = await createShare().json()
@@ -609,7 +609,7 @@ describe('Map Shares and Downloads', () => {
 				)
 				expect(declineResponse.status).toBe(409)
 				const declineError = await declineResponse.json()
-				expect(declineError).toHaveProperty('code', 'DECLINE_SHARE_NOT_PENDING')
+				expect(declineError).toHaveProperty('code', 'MAP_SHARE_CANCELED')
 			})
 
 			it('should return 404 when declining non-existent share', async (t) => {
@@ -1271,7 +1271,7 @@ describe('Map Shares and Downloads', () => {
 				const { createShare, sender, receiver } = await startServers(t)
 				const share = await createShare().json()
 
-				// First, cancel the share so decline will fail with DECLINE_SHARE_NOT_PENDING
+				// First, cancel the share so decline will fail with MAP_SHARE_CANCELED
 				await sender.post(`mapShares/${share.shareId}/cancel`)
 
 				// Now try to decline remotely - should get the error passed through
@@ -1288,7 +1288,7 @@ describe('Map Shares and Downloads', () => {
 
 				expect(response.status).toBe(409)
 				const error = await response.json()
-				expect(error).toHaveProperty('code', 'DECLINE_SHARE_NOT_PENDING')
+				expect(error).toHaveProperty('code', 'MAP_SHARE_CANCELED')
 			})
 		})
 	})