diff --git a/src/js_lexer.zig b/src/js_lexer.zig
index 12ba744ee1..b0f40e5d02 100644
--- a/src/js_lexer.zig
+++ b/src/js_lexer.zig
@@ -2335,7 +2335,7 @@ fn NewLexer_(
                                 lexer.step();
 
                                 if (isIdentifierStart(lexer.code_point)) {
-                                    while (isIdentifierStart(lexer.code_point) or lexer.code_point == '-') {
+                                    while (isIdentifierContinue(lexer.code_point) or lexer.code_point == '-') {
                                         lexer.step();
                                     }
                                 } else {
diff --git a/test/cli/run/jsx-namespaced-attributes.test.ts b/test/cli/run/jsx-namespaced-attributes.test.ts
new file mode 100644
index 0000000000..5143c06ca2
--- /dev/null
+++ b/test/cli/run/jsx-namespaced-attributes.test.ts
@@ -0,0 +1,10 @@
+import { expect, it } from "bun:test";
+import { nsExample1, nsExample2, nsExample3, nsExample4 } from "../../snippets/jsx-attributes.tsx";
+
+it("parses namespaced attributes correctly", () => {
+  expect(nsExample1.props).toEqual({ "ns:bar": "baz", "tag": true });
+  expect(nsExample2.props).toEqual({ "ns:bar42": "baz", "tag": false });
+  expect(nsExample3.props).toEqual({ "ns:bar42bar": "baz" });
+  expect(nsExample4.props).toEqual({ "ns42:bar": "baz" });
+});
+
diff --git a/test/snippets/jsx-attributes.tsx b/test/snippets/jsx-attributes.tsx
new file mode 100644
index 0000000000..f7e43ad611
--- /dev/null
+++ b/test/snippets/jsx-attributes.tsx
@@ -0,0 +1,47 @@
+// @ts-nocheck
+
+// Declare a minimally reproducible JSX namespace for testing;
+// ensures that no dependencies are required for this test.
+export interface JSXIntrinsicElements {
+  "ns:foo": {
+    "tag"?: boolean;
+    "ns:bar"?: string;
+    "ns:bar42"?: string;
+    "ns:bar42bar"?: string;
+    "ns42:bar"?: string;
+  };
+}
+
+// Minimal JSX element implementation.
+export class Element<T, P, C> {
+  constructor(
+    public readonly tag: T,
+    public readonly props: P,
+    public readonly children: C,
+  ) { }
+}
+
+export interface JsxElement extends Element<unknown, unknown, unknown> { }
+
+// JSX factory function used when compiling JSX with `jsx` pragma.
+// This is what the JSX transpiles to.
+export function jsx<T, P, C extends unknown[]>(
+  tag: T,
+  props: P,
+  ...children: C
+) {
+  return new Element(tag, props, children);
+}
+
+// Define the JSX namespace itself so TypeScript can resolve JSX
+// types correctly.
+export namespace jsx.JSX {
+  export interface Element extends JsxElement { }
+  export type IntrinsicElements = JSXIntrinsicElements;
+}
+
+// Examples of namespaced JSX attributes
+export const nsExample1 = <ns:foo tag ns:bar="baz" />;
+export const nsExample2 = <ns:foo tag={false} ns:bar42="baz" />;
+export const nsExample3 = <ns:foo ns:bar42bar="baz" />;
+export const nsExample4 = <ns:foo ns42:bar="baz" />;