diff --git a/src/misc/reaction-lib.ts b/src/misc/reaction-lib.ts
index a27fb883b1..7e5a1b0bc0 100644
--- a/src/misc/reaction-lib.ts
+++ b/src/misc/reaction-lib.ts
@@ -47,7 +47,7 @@ export async function toDbReaction(reaction: string, enableEmoji = true): Promis
 		return normalized;
 	}
 
-	const custom = reaction.match(/:([\w+-]+):/);
+	const custom = reaction.match(/^:([\w+-]+):$/);
 	if (custom) {
 		const emoji = await Emoji.findOne({
 			host: null,