diff --git a/competition/models.py b/competition/models.py
index 6dff6385..caea9723 100644
--- a/competition/models.py
+++ b/competition/models.py
@@ -210,6 +210,11 @@ class Meta:
         blank=True,
         default=None)
 
+    def save(self, *args, **kwargs) -> None:
+        if not self.frozen_results:
+            self.frozen_results = None
+        return super().save(*args, **kwargs)
+
     def get_first_series(self):
         return self.series_set.get(order=1)
 
@@ -257,6 +262,11 @@ class Meta:
         blank=True,
         default=None)
 
+    def save(self, *args, **kwargs) -> None:
+        if not self.frozen_results:
+            self.frozen_results = None
+        return super().save(*args, **kwargs)
+
     def __str__(self):
         return f'{self.semester} - {self.order}. séria'
 
@@ -421,6 +431,11 @@ class Meta:
     hidden_response = models.TextField(
         null=True, blank=True, verbose_name='Skrytá odpoveď na komentár')
 
+    def save(self, *args, **kwargs) -> None:
+        if not self.hidden_response:
+            self.hidden_response = None
+        return super().save(*args, **kwargs)
+
     def publish(self):
         self.state = CommentPublishState.PUBLISHED
         self.hidden_response = None