diff --git a/apps/server/src/modules/filesystem/controller.ts b/apps/server/src/modules/filesystem/controller.ts
index f85d883..6b1b17c 100644
--- a/apps/server/src/modules/filesystem/controller.ts
+++ b/apps/server/src/modules/filesystem/controller.ts
@@ -122,13 +122,22 @@ export class FilesystemController {
     const totalChunks = request.headers["x-total-chunks"] as string;
     const chunkSize = request.headers["x-chunk-size"] as string;
     const totalSize = request.headers["x-total-size"] as string;
-    const fileName = request.headers["x-file-name"] as string;
+    const encodedFileName = request.headers["x-file-name"] as string;
     const isLastChunk = request.headers["x-is-last-chunk"] as string;
 
-    if (!fileId || !chunkIndex || !totalChunks || !chunkSize || !totalSize || !fileName) {
+    if (!fileId || !chunkIndex || !totalChunks || !chunkSize || !totalSize || !encodedFileName) {
       return null;
     }
 
+    // Decode the base64-encoded filename to handle UTF-8 characters
+    let fileName: string;
+    try {
+      fileName = decodeURIComponent(escape(Buffer.from(encodedFileName, "base64").toString("binary")));
+    } catch (error) {
+      // Fallback to the encoded value if decoding fails (for backward compatibility)
+      fileName = encodedFileName;
+    }
+
     const metadata = {
       fileId,
       chunkIndex: parseInt(chunkIndex, 10),
diff --git a/apps/web/src/utils/chunked-upload.ts b/apps/web/src/utils/chunked-upload.ts
index 50104c2..e23b001 100644
--- a/apps/web/src/utils/chunked-upload.ts
+++ b/apps/web/src/utils/chunked-upload.ts
@@ -157,6 +157,10 @@ export class ChunkedUploader {
     url: string;
     signal?: AbortSignal;
   }): Promise<any> {
+    // Encode filename as base64 to handle UTF-8 characters in HTTP headers
+    // This prevents errors when setting headers with non-ASCII characters
+    const encodedFileName = btoa(unescape(encodeURIComponent(fileName)));
+
     const headers = {
       "Content-Type": "application/octet-stream",
       "X-File-Id": fileId,
@@ -164,7 +168,7 @@ export class ChunkedUploader {
       "X-Total-Chunks": totalChunks.toString(),
       "X-Chunk-Size": chunkSize.toString(),
       "X-Total-Size": totalSize.toString(),
-      "X-File-Name": fileName,
+      "X-File-Name": encodedFileName,
       "X-Is-Last-Chunk": isLastChunk.toString(),
     };