diff --git a/examples/files.ts b/examples/files.ts
new file mode 100644
index 0000000..640654a
--- /dev/null
+++ b/examples/files.ts
@@ -0,0 +1,8 @@
+import { OpenAI } from "../mod.ts";
+
+const openAI = new OpenAI(
+  "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",
+);
+
+// TODO: Do this more portably
+console.log(await openAI.uploadFile("./testdata/example.jsonl", "fine-tune"));
diff --git a/examples/testdata/example.jsonl b/examples/testdata/example.jsonl
new file mode 100644
index 0000000..e1b7c6a
--- /dev/null
+++ b/examples/testdata/example.jsonl
@@ -0,0 +1,4 @@
+{"prompt": "red", "completion": "angry"}
+{"prompt": "orange", "completion": "angry"}
+{"prompt": "blue", "completion": "calm"}
+{"prompt": "purple", "completion": "calm"}
\ No newline at end of file
diff --git a/src/openai.ts b/src/openai.ts
index e2dd0a1..f3e7af6 100644
--- a/src/openai.ts
+++ b/src/openai.ts
@@ -9,8 +9,9 @@ import type {
   EditOptions,
   Embedding,
   EmbeddingsOptions,
-  File,
+  FileInstance,
   FileList,
+  FileSpecifier,
   FineTune,
   FineTuneEvent,
   FineTuneEventList,
@@ -303,10 +304,33 @@ export class OpenAI {
    *
    * https://platform.openai.com/docs/api-reference/files/upload
    */
-  async uploadFile(file: string, purpose: string): Promise<File> {
-    return await this.#request(`/files`, {
-      file,
-      purpose,
+  async uploadFile(
+    file: FileSpecifier,
+    purpose: string,
+  ): Promise<FileInstance> {
+    const formData = new FormData();
+
+    // Model specified
+    formData.append("file", file);
+
+    // File data
+    if (typeof file === "string") {
+      const fileData = await Deno.readFile(file);
+
+      formData.append(
+        "file",
+        new File([fileData], basename(file)),
+      );
+    } else {
+      // Deno types are wrong
+      formData.append("file", file as unknown as Blob);
+    }
+
+    formData.append("purpose", purpose);
+
+    return await this.#request(`/files`, formData, {
+      noContentType: true,
+      method: "POST",
     });
   }
 
@@ -326,7 +350,7 @@ export class OpenAI {
    *
    * https://platform.openai.com/docs/api-reference/files/retrieve
    */
-  async retrieveFile(fileId: string): Promise<File> {
+  async retrieveFile(fileId: string): Promise<FileInstance> {
     return await this.#request(`/files/${fileId}`, undefined, {
       method: "GET",
     });
diff --git a/src/types.ts b/src/types.ts
index de0986e..48bf92a 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -669,7 +669,7 @@ export interface Translation {
   text: string;
 }
 
-export interface File {
+export interface FileInstance {
   id: string;
   object: "file";
   bytes: number;
@@ -679,7 +679,7 @@ export interface File {
 }
 
 export interface FileList {
-  data: File[];
+  data: FileInstance[];
   object: "list";
 }
 
@@ -714,10 +714,10 @@ export interface FineTune {
     prompt_loss_weight: number;
   };
   organization_id: string;
-  result_files: File[];
+  result_files: FileInstance[];
   status: "pending" | "succeeded" | "cancelled";
-  validation_files: File[];
-  training_files: File[];
+  validation_files: FileInstance[];
+  training_files: FileInstance[];
   updated_at: number;
 }