diff --git a/src/signals/path-matchers.ts b/src/signals/path-matchers.ts
index 3f5a2e69f8..5f80b6d09e 100644
--- a/src/signals/path-matchers.ts
+++ b/src/signals/path-matchers.ts
@@ -66,7 +66,7 @@ function isGeneratedFileFrom(parts: NormalizedPath): boolean {
     // Source maps for every first-class JS/TS bundle extension. `.mjs`/`.cjs` are already
     // recognized code extensions (isCodeFile), so their bundlers' `.mjs.map` / `.cjs.map`
     // maps are generated output too — the same as `.js.map`.
-    /\.(js|jsx|mjs|cjs|ts|tsx|mts|cts|vue|svelte|astro|scss|less|css)\.map$/.test(norm) ||
+    /\.(js|jsx|mjs|cjs|ts|tsx|mts|cts|vue|svelte|astro|mdx|scss|less|css)\.map$/.test(norm) ||
     base === "worker-configuration.d.ts"
   );
 }
diff --git a/test/unit/path-matchers.test.ts b/test/unit/path-matchers.test.ts
index f363acd404..45d6967abf 100644
--- a/test/unit/path-matchers.test.ts
+++ b/test/unit/path-matchers.test.ts
@@ -38,7 +38,7 @@ describe("isGeneratedFile", () => {
     }
   });
 
-  it("matches source maps for every first-class JS/TS and front-end framework extension", () => {
+  it("matches source maps for every first-class JS/TS, MDX, and front-end framework extension", () => {
     // `.mjs`/`.cjs` are recognized code extensions (isCodeFile), so their bundlers' source
     // maps are generated output too — the same as `.js.map` / `.tsx.map`.
     for (const path of [
@@ -50,6 +50,7 @@ describe("isGeneratedFile", () => {
       "dist/App.vue.map",
       "dist/Card.svelte.map",
       "dist/page.astro.map",
+      "dist/page.mdx.map",
       "dist/styles.scss.map",
       "dist/theme.less.map",
     ]) {