diff --git a/backend/helpers/ivantiApi.js b/backend/helpers/ivantiApi.js
index e101423..393c84c 100644
--- a/backend/helpers/ivantiApi.js
+++ b/backend/helpers/ivantiApi.js
@@ -109,11 +109,11 @@ function ivantiFormPost(urlPath, fields, files, apiKey, skipTls) {
     }
 
     // File fields
-    for (const { name, buffer, filename } of files) {
+    for (const { name, buffer, filename, contentType } of files) {
         parts.push(Buffer.from(
             `--${boundary}\r\n` +
             `Content-Disposition: form-data; name="${name}"; filename="${filename}"\r\n` +
-            `Content-Type: application/octet-stream\r\n\r\n`
+            `Content-Type: ${contentType || 'application/octet-stream'}\r\n\r\n`
         ));
         parts.push(buffer);
         parts.push(Buffer.from('\r\n'));
diff --git a/backend/routes/ivantiFpWorkflow.js b/backend/routes/ivantiFpWorkflow.js
index 15fe666..569b780 100644
--- a/backend/routes/ivantiFpWorkflow.js
+++ b/backend/routes/ivantiFpWorkflow.js
@@ -1048,10 +1048,10 @@ function createIvantiFpWorkflowRouter(db, requireAuth) {
                 console.log('[attachFiles] Uploading', files.length, 'files to', attachUrl);
 
                 for (const f of files) {
-                    console.log('[attachFiles] Uploading:', f.originalname, 'size:', f.size);
+                    console.log('[attachFiles] Uploading:', f.originalname, 'size:', f.size, 'mimetype:', f.mimetype);
                     try {
-                        // Use ivantiFormPost with field name 'files' (same as create endpoint)
-                        const formFiles = [{ name: 'files', buffer: f.buffer, filename: f.originalname }];
+                        // Use ivantiFormPost with field name 'file' and proper MIME type
+                        const formFiles = [{ name: 'file', buffer: f.buffer, filename: f.originalname, contentType: f.mimetype || 'application/octet-stream' }];
                         const result = await ivantiFormPost(attachUrl, [], formFiles, apiKey, skipTls);
                         console.log('[attachFiles] Result for', f.originalname, '— status:', result.status, 'body:', (result.body || '').substring(0, 200));
                         const success = result.status === 200 || result.status === 201 || result.status === 202;