diff --git a/ts/test-node/types/Attachment_test.std.ts b/ts/test-node/types/Attachment_test.std.ts
index 1aa6be8b0e..9afd636100 100644
--- a/ts/test-node/types/Attachment_test.std.ts
+++ b/ts/test-node/types/Attachment_test.std.ts
@@ -80,7 +80,7 @@ describe('Attachment', () => {
           attachment,
           timestamp,
         });
-        const expected = 'signal-1970-01-02-000000.mov';
+        const expected = 'signal-1970-01-02-00-00-00-000.mov';
         assert.strictEqual(actual, expected);
       });
     });
@@ -151,7 +151,7 @@ describe('Attachment', () => {
           timestamp,
           index: 3,
         });
-        const expected = 'signal-1970-01-02-000000_003.mov';
+        const expected = 'signal-1970-01-02-00-00-00-000_003.mov';
         assert.strictEqual(actual, expected);
       });
 
@@ -168,7 +168,7 @@ describe('Attachment', () => {
           timestamp,
           index: 1,
         });
-        const expected = 'signal-1970-01-02-000000.mov';
+        const expected = 'signal-1970-01-02-00-00-00-000.mov';
         assert.strictEqual(actual, expected);
       });
     });
diff --git a/ts/util/Attachment.std.ts b/ts/util/Attachment.std.ts
index 9259033390..e3da16ea47 100644
--- a/ts/util/Attachment.std.ts
+++ b/ts/util/Attachment.std.ts
@@ -673,7 +673,7 @@ export const getSuggestedFilename = ({
   }
 
   const suffix = timestamp
-    ? moment(timestamp).format('-YYYY-MM-DD-HHmmss')
+    ? moment(timestamp).format('-YYYY-MM-DD-HH-mm-ss-SSS')
     : '';
   const fileType = getFileExtension(attachment);
   const extension = fileType ? `.${fileType}` : '';
@@ -697,6 +697,8 @@ export const getFileExtension = (
       return 'mov';
     case 'audio/mpeg':
       return 'mp3';
+    case 'image/jpeg':
+      return 'jpg';
     default:
       return attachment.contentType.split('/')[1];
   }