diff --git a/filmovy-festival/home/models.py b/filmovy-festival/home/models.py
index d4e31b9..ffe7352 100644
--- a/filmovy-festival/home/models.py
+++ b/filmovy-festival/home/models.py
@@ -12,7 +12,7 @@ class HomePage(Page):
     body = RichTextField(blank=True)
     address = RichTextField(blank=True)
     image = models.ForeignKey(
-        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', on_delete=models.PROTECT, related_name='+'
     )
 
     content_panels = Page.content_panels + [
diff --git a/filmovy-festival/program/models.py b/filmovy-festival/program/models.py
index 50916e3..5124c20 100644
--- a/filmovy-festival/program/models.py
+++ b/filmovy-festival/program/models.py
@@ -13,7 +13,7 @@ class ProgramList(Page):
     year = models.PositiveIntegerField(blank=True)
     intro = RichTextField(blank=True)
     image = models.ForeignKey(
-        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', on_delete=models.PROTECT, related_name='+'
     )
 
     parent_page_types = ['home.HomePage', ]
@@ -33,7 +33,7 @@ class ProgramEntry(Page):
     country = models.CharField(max_length=64)
     annotation = RichTextField(blank=True)
     image = models.ForeignKey(
-        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', on_delete=models.PROTECT, related_name='+'
     )
 
     parent_page_types = ['program.ProgramList', ]
diff --git a/pension/tipy/models.py b/pension/tipy/models.py
index 5c5c125..92c962e 100644
--- a/pension/tipy/models.py
+++ b/pension/tipy/models.py
@@ -16,7 +16,7 @@ class TipyIndexPage(Page):
 class TipPage(Page):
     popisek = models.CharField(max_length=250)
     image = models.ForeignKey(
-        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', on_delete=models.PROTECT, related_name='+'
     )
 
     search_fields = Page.search_fields + [
diff --git a/showroom/catalog/models.py b/showroom/catalog/models.py
index dfe9b5e..646a88b 100644
--- a/showroom/catalog/models.py
+++ b/showroom/catalog/models.py
@@ -12,7 +12,7 @@ from wagtail.search import index
 class CategoryList(Page):
     intro = RichTextField(blank=True)
     image = models.ForeignKey(
-        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', on_delete=models.PROTECT, related_name='+'
     )
 
     parent_page_types = ['home.HomePage', ]
diff --git a/veterinarni-klinika/home/models.py b/veterinarni-klinika/home/models.py
index d4e31b9..ffe7352 100644
--- a/veterinarni-klinika/home/models.py
+++ b/veterinarni-klinika/home/models.py
@@ -12,7 +12,7 @@ class HomePage(Page):
     body = RichTextField(blank=True)
     address = RichTextField(blank=True)
     image = models.ForeignKey(
-        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', on_delete=models.PROTECT, related_name='+'
     )
 
     content_panels = Page.content_panels + [