diff --git a/seminar/models.py b/seminar/models.py
index 3042f61e..220e71ec 100644
--- a/seminar/models.py
+++ b/seminar/models.py
@@ -793,11 +793,14 @@ class Organizator(models.Model):
         verbose_name_plural = 'Organizátoři'
 
     def save(self):
+        if self.id is not None:
+            puvodni = Organizator.objects.get(id=self.id)
         if self.foto:
-            original = Image.open(self.foto)
-            jmeno = os.path.basename(self.foto.file.name)
-            Organizator._vyrobMiniaturu(original, jmeno, 500, self.foto)
-            Organizator._vyrobMiniaturu(original, jmeno, 200, self.foto_male)
+            if not puvodni or puvodni.foto != self.foto:
+                original = Image.open(self.foto)
+                jmeno = os.path.basename(self.foto.file.name)
+                Organizator._vyrobMiniaturu(original, jmeno, 500, self.foto)
+                Organizator._vyrobMiniaturu(original, jmeno, 200, self.foto_male)
         super(Organizator, self).save()
 
     @staticmethod