diff --git a/lib/www/server/lib/db/event/patch.js b/lib/www/server/lib/db/event/patch.js
index 3eefae6..f4fd51c 100644
--- a/lib/www/server/lib/db/event/patch.js
+++ b/lib/www/server/lib/db/event/patch.js
@@ -5,6 +5,8 @@ async function patch (projectId, eventId, payload, opts = {}) {
 	const p = payload; // Shorter
 	const client = await setSurvey(projectId);
 	try {
+		await transaction.begin(client);
+
 		// The order of attributes in an object is not defined, so
 		// in theory we could get a different order if we made separate
 		// calls to Object.keys() and Object.values(), unlikely as that
@@ -22,10 +24,32 @@ async function patch (projectId, eventId, payload, opts = {}) {
 		const values = [ eventId, ...v ];
 
 		await client.query(text, values);
+
+		// NOTE Horrible hack warning.
+		// If we try to do the UPDATE on event_log, as you normally would,
+		// we get a constraint violation on `event_log_full_validity_check`.
+		// We would normally set that constraint as DEFERRABLE, except that
+		// as of version 14, PostgreSQL does not support deferrable CHECK
+		// constraints:
+		// https://www.postgresql.org/docs/current/sql-createtable.html
+		// So the options that I can think of are either not to use a transaction
+		// or to apply this second update directly on the `event_log_full` table.
+
+		const text1 = `
+			UPDATE event_log_full
+			SET remarks = replace_placeholders(remarks, tstamp, sequence, point)
+			WHERE id = $1 AND validity @> current_timestamp;
+		`;
+		const values1 = [ eventId ];
+
+		await client.query(text1, values1);
+
+		await transaction.commit(client);
 	} catch (err) {
+		err.origin = __filename;
 		throw err;
 	} finally {
-		client.release();
+		client.release(); // implies ROLLBACK;
 	}
 
 	return;
diff --git a/lib/www/server/lib/db/event/post.js b/lib/www/server/lib/db/event/post.js
index 0adaf55..d213a22 100644
--- a/lib/www/server/lib/db/event/post.js
+++ b/lib/www/server/lib/db/event/post.js
@@ -10,7 +10,7 @@ async function post (projectId, payload, opts = {}) {
 		const text = `
 			INSERT
 			INTO event_log (tstamp, sequence, point, remarks, labels)
-			VALUES ($1, $2, $3, $4, $5);
+			VALUES ($1, $2, $3, replace_placeholders($4, $1, $2, $3), $5);
 		`;
 		const values = [ p.tstamp, p.sequence, p.point, p.remarks, p.labels ];
 
diff --git a/lib/www/server/lib/db/event/put.js b/lib/www/server/lib/db/event/put.js
index 744555f..699288b 100644
--- a/lib/www/server/lib/db/event/put.js
+++ b/lib/www/server/lib/db/event/put.js
@@ -12,7 +12,7 @@ async function put (projectId, eventId, payload, opts = {}) {
 				tstamp = $1,
 				sequence = $2,
 				point = $3,
-				remarks = $4,
+				remarks = replace_placeholders($4, $1, $2, $3),
 				labels = $5
 			WHERE id = $6;
 		`;