diff --git a/bootstrapvz/common/tasks/apt.py b/bootstrapvz/common/tasks/apt.py
index 07b8bd3..a5b2ff5 100644
--- a/bootstrapvz/common/tasks/apt.py
+++ b/bootstrapvz/common/tasks/apt.py
@@ -64,12 +64,21 @@ class AddDefaultSources(Task):
         if include_src:
             info.source_lists.add('main', 'deb-src {apt_mirror} {system.release} ' + components)
         if info.manifest.release != sid and info.manifest.release >= wheezy:
-            info.source_lists.add('main', 'deb     {apt_security} {system.release}/updates ' + components)
-            if include_src:
-                info.source_lists.add('main', 'deb-src {apt_security} {system.release}/updates ' + components)
-            info.source_lists.add('main', 'deb     {apt_mirror} {system.release}-updates ' + components)
-            if include_src:
-                info.source_lists.add('main', 'deb-src {apt_mirror} {system.release}-updates ' + components)
+            if info.manifest.release < bullseye:
+                info.source_lists.add('main', 'deb     {apt_security} {system.release}/updates ' + components)
+                if include_src:
+                    info.source_lists.add('main', 'deb-src {apt_security} {system.release}/updates ' + components)
+                info.source_lists.add('main', 'deb     {apt_mirror} {system.release}-updates ' + components)
+                if include_src:
+                    info.source_lists.add('main', 'deb-src {apt_mirror} {system.release}-updates ' + components)
+            else:
+                if info.manifest.release < bullseye:
+                    info.source_lists.add('main', 'deb     {apt_security}debian-security {system.release}-security ' + components)
+                    if include_src:
+                        info.source_lists.add('main', 'deb-src {apt_security}debian-security {system.release}-security ' + components)
+                    info.source_lists.add('main', 'deb     {apt_mirror}debian-security {system.release}-security ' + components)
+                    if include_src:
+                        info.source_lists.add('main', 'deb-src {apt_mirror}debian-security {system.release}-security ' + components)
 
 
 class AddBackports(Task):