diff --git a/app/containers/message/Markdown.js b/app/containers/message/Markdown.js
index bb6ab1e6..328eaae1 100644
--- a/app/containers/message/Markdown.js
+++ b/app/containers/message/Markdown.js
@@ -29,7 +29,7 @@ const BlockCode = ({ node, state }) => (
 const rules = {
 	username: {
 		order: -1,
-		match: SimpleMarkdown.inlineRegex(/@[0-9a-zA-Z-_.]+/),
+		match: SimpleMarkdown.inlineRegex(/^@[0-9a-zA-Z-_.]+/),
 		parse: capture => ({ content: capture[0] }),
 		react: (node, output, state) => ({
 			type: 'custom',
@@ -49,7 +49,7 @@ const rules = {
 	},
 	heading: {
 		order: -2,
-		match: SimpleMarkdown.inlineRegex(/#[0-9a-zA-Z-_.]+/),
+		match: SimpleMarkdown.inlineRegex(/^#[0-9a-zA-Z-_.]+/),
 		parse: capture => ({ content: capture[0] }),
 		react: (node, output, state) => ({
 			type: 'custom',