diff --git a/public/src/modules/helpers.common.js b/public/src/modules/helpers.common.js
index 820b0c09b3..b426fdaf51 100644
--- a/public/src/modules/helpers.common.js
+++ b/public/src/modules/helpers.common.js
@@ -27,6 +27,7 @@ module.exports = function (utils, Benchpress, relative_path) {
 		increment,
 		generateRepliedTo,
 		generateWrote,
+		encodeURIComponent: _encodeURIComponent,
 		isoTimeToLocaleString,
 		shouldHideReplyContainer,
 		humanReadableNumber,
@@ -340,13 +341,17 @@ module.exports = function (utils, Benchpress, relative_path) {
 			post.parent.displayname : '[[global:guest]]';
 		const isBeforeCutoff = post.timestamp < (Date.now() - (timeagoCutoff * oneDayInMs));
 		const langSuffix = isBeforeCutoff ? 'on' : 'ago';
-		return `[[topic:replied-to-user-${langSuffix}, ${post.toPid}, ${relative_path}/post/${post.toPid}, ${displayname}, ${relative_path}/post/${post.pid}, ${post.timestampISO}]]`;
+		return `[[topic:replied-to-user-${langSuffix}, ${post.toPid}, ${relative_path}/post/${encodeURIComponent(post.toPid)}, ${displayname}, ${relative_path}/post/${encodeURIComponent(post.pid)}, ${post.timestampISO}]]`;
 	}
 
 	function generateWrote(post, timeagoCutoff) {
 		const isBeforeCutoff = post.timestamp < (Date.now() - (timeagoCutoff * oneDayInMs));
 		const langSuffix = isBeforeCutoff ? 'on' : 'ago';
-		return `[[topic:wrote-${langSuffix}, ${relative_path}/post/${post.pid}, ${post.timestampISO}]]`;
+		return `[[topic:wrote-${langSuffix}, ${relative_path}/post/${encodeURIComponent(post.pid)}, ${post.timestampISO}]]`;
+	}
+
+	function _encodeURIComponent(value) {
+		return encodeURIComponent(value);
 	}
 
 	function isoTimeToLocaleString(isoTime, locale = 'en-GB') {
diff --git a/src/activitypub/inbox.js b/src/activitypub/inbox.js
index 49c50f4ab1..e224ab1599 100644
--- a/src/activitypub/inbox.js
+++ b/src/activitypub/inbox.js
@@ -154,7 +154,7 @@ inbox.announce = async (req) => {
 	await topics.events.log(tid, {
 		type: 'announce',
 		uid: actor,
-		href: `/post/${pid}`,
+		href: `/post/${encodeURIComponent(pid)}`,
 		pid,
 		timestamp,
 	});