diff --git a/web/static/src/ts/core/qweb_vdom.ts b/web/static/src/ts/core/qweb_vdom.ts
index 49b41a07..747c1575 100644
--- a/web/static/src/ts/core/qweb_vdom.ts
+++ b/web/static/src/ts/core/qweb_vdom.ts
@@ -425,7 +425,11 @@ export class QWeb {
       }
 
       if (name.startsWith("t-attf-")) {
-        const attName = name.slice(7);
+        let attName = name.slice(7);
+        if (!attName.match(/^[a-zA-Z]+$/)) {
+          // attribute contains 'non letters' => we want to quote it
+          attName = '"' + attName + '"';
+        }
         const formattedExpr = value!.replace(
           /\{\{.*?\}\}/g,
           s => "${" + this._formatExpression(s.slice(2, -2)) + "}"
diff --git a/web/static/tests/core/__snapshots__/qweb_vdom.test.ts.snap b/web/static/tests/core/__snapshots__/qweb_vdom.test.ts.snap
index fe1e29c9..2632eda1 100644
--- a/web/static/tests/core/__snapshots__/qweb_vdom.test.ts.snap
+++ b/web/static/tests/core/__snapshots__/qweb_vdom.test.ts.snap
@@ -33,6 +33,17 @@ exports[`attributes dynamic attributes 1`] = `
 }"
 `;
 
+exports[`attributes dynamic formatted attributes with a dash 1`] = `
+"function anonymous(context,extra
+) {
+    let h = this.h;
+    let _1 = \`Some text \${context['id']}\`;
+    let c2 = [], p2 = {key:2,attrs:{\\"aria-label\\": _1}};
+    let vn2 = h('div', p2, c2);
+    return vn2;
+}"
+`;
+
 exports[`attributes fixed variable 1`] = `
 "function anonymous(context,extra
 ) {
diff --git a/web/static/tests/core/qweb_vdom.test.ts b/web/static/tests/core/qweb_vdom.test.ts
index cf3a0e7d..3435650e 100644
--- a/web/static/tests/core/qweb_vdom.test.ts
+++ b/web/static/tests/core/qweb_vdom.test.ts
@@ -316,6 +316,12 @@ describe("attributes", () => {
     expect(result).toBe(`<div data-action-id="32"></div>`);
   });
 
+  test("dynamic formatted attributes with a dash", () => {
+    qweb.addTemplate("test", `<div t-attf-aria-label="Some text {{id}}"/>`);
+    const result = renderToString(qweb, "test", { id: 32 });
+    expect(result).toBe(`<div aria-label="Some text 32"></div>`);
+  });
+
   test("fixed variable", () => {
     qweb.addTemplate("test", `<div t-att-foo="value"/>`);
     const result = renderToString(qweb, "test", { value: "ok" });