diff --git a/src/editor/deserialize.ts b/src/editor/deserialize.ts
index 6680029130..5322f09f11 100644
--- a/src/editor/deserialize.ts
+++ b/src/editor/deserialize.ts
@@ -53,7 +53,7 @@ function parseLink(a: HTMLAnchorElement, partCreator: PartCreator) {
             if (href === a.textContent) {
                 return partCreator.plain(a.textContent);
             } else {
-                return partCreator.plain(`[${a.textContent.replace(/[\\\]]/, c => "\\" + c)}](${href})`);
+                return partCreator.plain(`[${a.textContent.replace(/[[\\\]]/, c => "\\" + c)}](${href})`);
             }
         }
     }
diff --git a/src/editor/serialize.ts b/src/editor/serialize.ts
index 9ff1cfbd80..d501bdd47e 100644
--- a/src/editor/serialize.ts
+++ b/src/editor/serialize.ts
@@ -31,7 +31,7 @@ export function mdSerialize(model: EditorModel) {
                 return html + part.text;
             case "room-pill":
             case "user-pill":
-                return html + `[${part.text.replace(/[\\\]]/, c => "\\" + c)}](${makeGenericPermalink(part.resourceId)})`;
+                return html + `[${part.text.replace(/[[\\\]]/, c => "\\" + c)}](${makeGenericPermalink(part.resourceId)})`;
         }
     }, "");
 }
diff --git a/test/editor/deserialize-test.js b/test/editor/deserialize-test.js
index 4184552559..fb97d75752 100644
--- a/test/editor/deserialize-test.js
+++ b/test/editor/deserialize-test.js
@@ -156,6 +156,14 @@ describe('editor/deserialize', function() {
             expect(parts[1]).toStrictEqual({type: "user-pill", text: "Alice\\", resourceId: "@alice:hs.tld"});
             expect(parts[2]).toStrictEqual({type: "plain", text: "!"});
         });
+        it('user pill with displayname containing opening square bracket', function() {
+            const html = "Hi <a href=\"https://matrix.to/#/@alice:hs.tld\">Alice[</a>!";
+            const parts = normalize(parseEvent(htmlMessage(html), createPartCreator()));
+            expect(parts.length).toBe(3);
+            expect(parts[0]).toStrictEqual({type: "plain", text: "Hi "});
+            expect(parts[1]).toStrictEqual({type: "user-pill", text: "Alice[", resourceId: "@alice:hs.tld"});
+            expect(parts[2]).toStrictEqual({type: "plain", text: "!"});
+        });
         it('user pill with displayname containing closing square bracket', function() {
             const html = "Hi <a href=\"https://matrix.to/#/@alice:hs.tld\">Alice]</a>!";
             const parts = normalize(parseEvent(htmlMessage(html), createPartCreator()));
diff --git a/test/editor/serialize-test.js b/test/editor/serialize-test.js
index a69e3598e3..a114f89de2 100644
--- a/test/editor/serialize-test.js
+++ b/test/editor/serialize-test.js
@@ -49,6 +49,12 @@ describe('editor/serialize', function() {
         const html = htmlSerializeIfNeeded(model, {});
         expect(html).toBe("<a href=\"https://matrix.to/#/@user:server\">Displayname\\</a>");
     });
+    it('displaynames containing an opening square bracket work', function() {
+        const pc = createPartCreator();
+        const model = new EditorModel([pc.userPill("Displayname[", "@user:server")]);
+        const html = htmlSerializeIfNeeded(model, {});
+        expect(html).toBe("<a href=\"https://matrix.to/#/@user:server\">Displayname[</a>");
+    });
     it('displaynames containing a closing square bracket work', function() {
         const pc = createPartCreator();
         const model = new EditorModel([pc.userPill("Displayname]", "@user:server")]);