diff --git a/app/__test__/media/mime-types.spec.ts b/app/__test__/media/mime-types.spec.ts
index dd13f7c..d326aca 100644
--- a/app/__test__/media/mime-types.spec.ts
+++ b/app/__test__/media/mime-types.spec.ts
@@ -71,6 +71,7 @@ describe("media/mime-types", () => {
          ["application/zip", "zip"],
          ["text/tab-separated-values", "tsv"],
          ["application/zip", "zip"],
+         ["application/pdf", "pdf"],
       ] as const;
 
       for (const [mime, ext] of tests) {
@@ -88,6 +89,7 @@ describe("media/mime-types", () => {
          ["image.jpeg", "jpeg"],
          ["-473Wx593H-466453554-black-MODEL.jpg", "jpg"],
          ["-473Wx593H-466453554-black-MODEL.avif", "avif"],
+         ["file.pdf", "pdf"],
       ] as const;
 
       for (const [filename, ext] of tests) {
@@ -102,4 +104,28 @@ describe("media/mime-types", () => {
       const [, ext] = getRandomizedFilename(file).split(".");
       expect(ext).toBe("jpg");
    });
+
+   test("getRandomizedFilename with body", async () => {
+      // should keep "pdf"
+      const [, ext] = getRandomizedFilename(
+         new File([""], "file.pdf", { type: "application/pdf" }),
+      ).split(".");
+      expect(ext).toBe("pdf");
+
+      {
+         // no ext, should use "pdf" only for known formats
+         const [, ext] = getRandomizedFilename(
+            new File([""], "file", { type: "application/pdf" }),
+         ).split(".");
+         expect(ext).toBe("pdf");
+      }
+
+      {
+         // wrong ext, should keep the wrong one
+         const [, ext] = getRandomizedFilename(
+            new File([""], "file.what", { type: "application/pdf" }),
+         ).split(".");
+         expect(ext).toBe("what");
+      }
+   });
 });
diff --git a/app/src/media/storage/mime-types-tiny.ts b/app/src/media/storage/mime-types-tiny.ts
index e7c42bb..6a3e241 100644
--- a/app/src/media/storage/mime-types-tiny.ts
+++ b/app/src/media/storage/mime-types-tiny.ts
@@ -3,7 +3,7 @@ export const Q = {
    audio: ["ogg"],
    image: ["jpeg", "png", "gif", "webp", "bmp", "tiff", "avif", "heic", "heif"],
    text: ["html", "css", "mdx", "yaml", "vcard", "csv", "vtt"],
-   application: ["zip", "xml", "toml", "json", "json5"],
+   application: ["zip", "xml", "toml", "json", "json5", "pdf"],
    font: ["woff", "woff2", "ttf", "otf"],
 } as const;
 
@@ -19,7 +19,7 @@ const c = {
 export const M = new Map<string, string>([
    ["7z", c.z],
    ["7zip", c.z],
-   ["ai", c.a("pdf")],
+   ["ai", c.a("postscript")],
    ["apk", c.a("vnd.android.package-archive")],
    ["doc", c.a("msword")],
    ["docx", `${c.vnd}.wordprocessingml.document`],