diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index 76cc8af01b..e5a8e8e363 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -42,7 +42,7 @@ const sanitizeConfig = {
 
 Mocks._normalize = async (object) => {
 	// Normalized incoming AP objects into expected types for easier mocking
-	let { type, attributedTo, url, image, mediaType, content, source, attachment } = object;
+	let { type, attributedTo, url, image, mediaType, content, source, attachment, cc } = object;
 
 	switch (true) { // non-string attributedTo handling
 		case Array.isArray(attributedTo): {
@@ -52,6 +52,10 @@ Mocks._normalize = async (object) => {
 				} else if (typeof cur === 'object') {
 					if (cur.type === 'Person' && cur.id) {
 						valid.push(cur.id);
+					} else if (cur.type === 'Group' && cur.id) {
+						// Add any groups found to cc where it is expected
+						cc = Array.isArray(cc) ? cc : [cc];
+						cc.push(cur.id);
 					}
 				}
 
@@ -148,6 +152,7 @@ Mocks._normalize = async (object) => {
 
 	return {
 		...object,
+		cc,
 		attributedTo,
 		content,
 		sourceContent,
diff --git a/src/activitypub/notes.js b/src/activitypub/notes.js
index 31ca249d3d..616fc3a44f 100644
--- a/src/activitypub/notes.js
+++ b/src/activitypub/notes.js
@@ -115,18 +115,33 @@ Notes.assert = async (uid, input, options = { skipChecks: false }) => {
 	if (hasTid) {
 		mainPid = await topics.getTopicField(tid, 'mainPid');
 	} else {
-		// Check recipients/audience for local category
+		// Check recipients/audience for category (local or remote)
 		const set = activitypub.helpers.makeSet(_activitypub, ['to', 'cc', 'audience']);
 		await activitypub.actors.assert(Array.from(set));
+
+		// Local
 		const resolved = await Promise.all(Array.from(set).map(async id => await activitypub.helpers.resolveLocalId(id)));
 		const recipientCids = resolved
 			.filter(Boolean)
 			.filter(({ type }) => type === 'category')
 			.map(obj => obj.id);
 
-		if (recipientCids.length) {
+		// Remote
+		let remoteCid;
+		const assertedGroups = await categories.exists(Array.from(set));
+		try {
+			const { hostname } = new URL(mainPid);
+			remoteCid = Array.from(set).filter((id, idx) => {
+				const { hostname: cidHostname } = new URL(id);
+				return assertedGroups[idx] && cidHostname === hostname;
+			}).shift();
+		} catch (e) {
+			// noop
+		}
+
+		if (remoteCid || recipientCids.length) {
 			// Overrides passed-in value, respect addressing from main post over booster
-			options.cid = recipientCids.shift();
+			options.cid = remoteCid || recipientCids.shift();
 		}
 
 		// mainPid ok to leave as-is