diff --git a/lib/popups/tasks_popups/signature_popup.dart b/lib/popups/tasks_popups/signature_popup.dart
index a05d750..6e3f5c0 100644
--- a/lib/popups/tasks_popups/signature_popup.dart
+++ b/lib/popups/tasks_popups/signature_popup.dart
@@ -74,7 +74,11 @@ showSignaturePopup(BuildContext context, TaskInfo taskInfo, Function(String?) on
                             getDefaultButton('Übernehmen', buttonHeight: 50, () => {
                               Navigator.of(context).pop(),
 
-                              onFinished(convertPoints(controller.points))
+                              if (controller.points.length > 50) {
+                                onFinished(convertPoints(controller.points))
+                              } else {
+                                showAlertDialog(context, "Fehler", "Die Unterschrift ist zu kurz.")
+                              }
                             })
                           ],
                         ),