diff --git a/addonsu/51-addonsu.sh b/addonsu/51-addonsu.sh
index 895496d..f2d200b 100644
--- a/addonsu/51-addonsu.sh
+++ b/addonsu/51-addonsu.sh
@@ -1,4 +1,7 @@
 #!/sbin/sh
+#
+# ADDOND_VERSION=2
+#
 
 . /tmp/backuptool.functions
 
diff --git a/prebuilt/common/bin/50-lineage.sh b/prebuilt/common/bin/50-lineage.sh
index cf9d815..e5cf000 100755
--- a/prebuilt/common/bin/50-lineage.sh
+++ b/prebuilt/common/bin/50-lineage.sh
@@ -1,5 +1,7 @@
 #!/sbin/sh
 #
+# ADDOND_VERSION=2
+#
 # /system/addon.d/50-lineage.sh
 # During a LineageOS 15.1 upgrade, this script backs up /system/etc/hosts,
 # /system is formatted and reinstalled, then the file is restored.
diff --git a/prebuilt/common/bin/backuptool.sh b/prebuilt/common/bin/backuptool.sh
index 61b4d89..8d85a64 100755
--- a/prebuilt/common/bin/backuptool.sh
+++ b/prebuilt/common/bin/backuptool.sh
@@ -7,6 +7,8 @@
 export S=/system
 export V=15.1
 
+export ADDOND_VERSION=1
+
 # Scripts in /system/addon.d expect to find backuptool.functions in /tmp
 cp -f /tmp/install/bin/backuptool.functions /tmp
 
@@ -15,6 +17,18 @@
   if [ -d /system/addon.d/ ]; then
     mkdir -p /tmp/addon.d/
     cp -a /system/addon.d/* /tmp/addon.d/
+
+    # Discard any scripts that aren't at least our version level
+    for f in /postinstall/tmp/addon.d/*sh; do
+      SCRIPT_VERSION=$(grep "^# ADDOND_VERSION=" $f | cut -d= -f2)
+      if [ -z "$SCRIPT_VERSION" ]; then
+        SCRIPT_VERSION=1
+      fi
+      if [ $SCRIPT_VERSION -lt $ADDOND_VERSION ]; then
+        rm $f
+      fi
+    done
+
     chmod 755 /tmp/addon.d/*.sh
   fi
 }
diff --git a/prebuilt/common/bin/backuptool_ab.sh b/prebuilt/common/bin/backuptool_ab.sh
index 26034a4..70be0ae 100755
--- a/prebuilt/common/bin/backuptool_ab.sh
+++ b/prebuilt/common/bin/backuptool_ab.sh
@@ -7,6 +7,8 @@
 export C=/postinstall/tmp/backupdir
 export V=15.1
 
+export ADDOND_VERSION=2
+
 # Scripts in /system/addon.d expect to find backuptool.functions in /tmp
 mkdir -p /postinstall/tmp/
 cp -f /postinstall/system/bin/backuptool_ab.functions /postinstall/tmp/backuptool.functions
@@ -16,6 +18,18 @@
   if [ -d /system/addon.d/ ]; then
     mkdir -p /postinstall/tmp/addon.d/
     cp -a /system/addon.d/* /postinstall/tmp/addon.d/
+
+    # Discard any scripts that aren't at least our version level
+    for f in /postinstall/tmp/addon.d/*sh; do
+      SCRIPT_VERSION=$(grep "^# ADDOND_VERSION=" $f | cut -d= -f2)
+      if [ -z "$SCRIPT_VERSION" ]; then
+        SCRIPT_VERSION=1
+      fi
+      if [ $SCRIPT_VERSION -lt $ADDOND_VERSION ]; then
+        rm $f
+      fi
+    done
+
     chmod 755 /postinstall/tmp/addon.d/*.sh
   fi
 }