diff --git a/src/activitypub/helpers.js b/src/activitypub/helpers.js
index 80135808ab..a966d26ac0 100644
--- a/src/activitypub/helpers.js
+++ b/src/activitypub/helpers.js
@@ -65,10 +65,11 @@ Helpers.isUri = (value) => {
 	});
 };
 
-Helpers.assertAccept = accept => (accept && accept.split(',').some((value) => {
-	const parts = value.split(';').map(v => v.trim());
-	return activitypub._constants.acceptableTypes.includes(value || parts[0]);
-}));
+Helpers.assertAccept = (accept) => {
+	if (!accept) return false;
+	const normalized = accept.split(',').map(s => s.trim().replace(/\s*;\s*/g, ';')).join(',');
+	return activitypub._constants.acceptableTypes.some(type => normalized.includes(type));
+};
 
 Helpers.isWebfinger = (value) => {
 	// N.B. returns normalized handle, so truthy check!
diff --git a/src/activitypub/index.js b/src/activitypub/index.js
index 92dd10b544..4ab6159f2f 100644
--- a/src/activitypub/index.js
+++ b/src/activitypub/index.js
@@ -41,7 +41,7 @@ ActivityPub._constants = Object.freeze({
 	acceptablePublicAddresses: ['https://www.w3.org/ns/activitystreams#Public', 'as:Public', 'Public'],
 	acceptableTypes: [
 		'application/activity+json',
-		'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
+		'application/ld+json;profile="https://www.w3.org/ns/activitystreams"',
 	],
 	acceptedPostTypes: [
 		'Note', 'Page', 'Article', 'Question', 'Video',