diff --git a/README.md b/README.md
index b5473f6..447b460 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,8 @@ The addon.d script can not be copied into `system/addon.d` since system is mount
 This module will overlay a copy of the addon.d script into `system/addon.d`.<br>
 <i>So it can be found and run with other addon.d script(s) during a system OTA update.</i>
 
-<b>Note: This module only works with addon.d-v2 (A/B slot devices).</b>
+<b>Note: This module only works with addon.d-v2 (A/B slot devices).</b><br>
+<b>Install Magisk before installing this module.</b>
 
 ## Warning
 This module is only <i>systemless</i> before the first OTA update.<br>
@@ -30,13 +31,14 @@ After the first OTA update, this module is no longer needed and can be disabled
 Available in the releases tab. [Link](https://github.com/mModule/mSurvival/releases)
 
 ### Install
-- Copy the zip file to the device.
+- Install Magisk first (boot patch or recovery zip).
+- Copy the module zip file to the device.
 - Open Magisk, select Modules and then Install from storage.
 - Reboot device
 
 ### Recent changes
+- Validate Magisk addon.d source before copy; fail install on copy errors.
 - Initial release.
-- Not planned for long-term support.
 
 ### Notes
 - Feel free to use, change, improve, adapt.
diff --git a/customize.sh b/customize.sh
index 80bc8ad..3506522 100755
--- a/customize.sh
+++ b/customize.sh
@@ -1,44 +1,40 @@
 #!/system/bin/sh
 
 ## Magisk OTA Survival module.
-## This module will overlay Magisk's addon.d script into the system/addon.d directory if it exists.
-## ipdev @ xda-developers
+## Overlays Magisk's addon.d script into system/addon.d when boot-patched installs skip it.
 
-# __ Define variables. __
-
-### Magisk variables
-## MODPATH (path): the path where your module files should be installed.
-
-# ADB Directory
 ADB=/data/adb
+MAGISK_ADDON="$ADB/magisk/addon.d.sh"
+MODULE_ID=MagiskSurvival
+TARGET="$MODPATH/system/addon.d/99-magisk.sh"
+
+abort_install() {
+	echo "! $1" >&2
+	echo " This module will not be installed." >&2
+	rm -rf "$ADB/modules_update/$MODULE_ID"
+	exit 1
+}
 
-# __ Define functions. __
-
-### Magisk functions
-## set_perm <target> <owner> <group> <permission> [context]
-
-# __ Here we go. __
-
-if [ -d /system/addon.d ]; then
-	# Make the module addon.d directory if it does not exist.
-	if [ ! -d "$MODPATH"/system/addon.d ]; then
-		mkdir -p "$MODPATH"/system/addon.d
-	else
-		# Remove the previous addon.d script.
-		rm "$MODPATH"/system/addon.d/99-magisk.sh
-	fi
+if [ ! -d /system/addon.d ]; then
+	abort_install "Survival (addon.d) scripts are not supported on this ROM."
+fi
 
-	# Copy the current addon.d script from magisk to the module directory.
-	cp "$ADB"/magisk/addon.d.sh "$MODPATH"/system/addon.d/99-magisk.sh
+if [ ! -f "$MAGISK_ADDON" ]; then
+	abort_install "Magisk addon.d.sh not found at $MAGISK_ADDON. Install Magisk first."
+fi
 
-	# Set owner, group, permission and security.
-	set_perm "$MODPATH"/system/addon.d/99-magisk.sh 0 0 0755 u:object_r:system_file:s0
+if [ ! -d "$MODPATH/system/addon.d" ]; then
+	mkdir -p "$MODPATH/system/addon.d"
 else
-	echo "Survival (addon.d) scripts are not supported."
-	echo " This module will not be installed."
-	rm -rf "$ADB"/modules_update/MagiskSurvival
-	exit 1
+	rm -f "$TARGET"
 fi
 
-# __ Finish and Cleanup. __
+if ! cp "$MAGISK_ADDON" "$TARGET"; then
+	abort_install "Failed to copy Magisk addon.d script into module overlay."
+fi
+
+if [ ! -f "$TARGET" ]; then
+	abort_install "addon.d overlay script missing after copy."
+fi
 
+set_perm "$TARGET" 0 0 0755 u:object_r:system_file:s0
diff --git a/mSurvival.json b/mSurvival.json
index 106ec5c..65d0d5e 100644
--- a/mSurvival.json
+++ b/mSurvival.json
@@ -1,6 +1,6 @@
 {
-  "versionCode": "10",
-  "version": "Module (v1)",
-  "zipUrl": "https://github.com/mModule/mSurvival/releases/download/v1/MagiskSurvival-v1.zip",
-  "changelog": "https://github.com/mModule/mSurvival/releases/download/v1/v1.md"
+  "versionCode": "11",
+  "version": "Module (v1.1)",
+  "zipUrl": "https://github.com/mModule/mSurvival/releases/download/v1.1/MagiskSurvival-v1.1.zip",
+  "changelog": "https://github.com/mModule/mSurvival/releases/download/v1.1/v1.1.md"
 }
diff --git a/module.prop b/module.prop
index a016f23..09d9d1d 100755
--- a/module.prop
+++ b/module.prop
@@ -1,7 +1,7 @@
 id=MagiskSurvival
 name=Magisk Survival Script
-version=Module (v1)
-versionCode=10
+version=Module (v1.1)
+versionCode=11
 author=ip
-description=Magisk Survival (addon.d) script.
+description=Magisk Survival (addon.d) script for boot-patched installs.
 updateJson=https://raw.githubusercontent.com/mModule/mSurvival/master/mSurvival.json