diff --git a/Makefile b/Makefile
index 5f420c0..50590b0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=blue-merle
-PKG_VERSION:=1.0.0
+PKG_VERSION:=1.1.0
 PKG_RELEASE:=$(AUTORELEASE)
 
 PKG_MAINTAINER:=Matthias <matthias@srlabs.de>
@@ -12,7 +12,7 @@ include $(INCLUDE_DIR)/package.mk
 define Package/blue-merle
 	SECTION:=utils
 	CATEGORY:=Utilities
-	DEPENDS:=+bash +coreutils-shred +python3 +python3-pyserial +patch
+	DEPENDS:=gl-ui gl-e750-mcu +bash +coreutils-shred +python3 +python3-pyserial +patch
 	TITLE:=Anonymity Enhancements for GL-E750 Mudi
 endef
 
@@ -96,13 +96,27 @@ define Package/blue-merle/preinst
 		}
 
 	if grep -q "GL.iNet GL-E750" /proc/cpuinfo; then
-		if grep -q -w "3.215" /etc/glversion; then
-			CHECK_MCUVERSION
-			echo "Device is supported, installing blue-merle."
-			exit 0
-		else
-			ABORT_GLVERSION
-		fi
+	    GL_VERSION=$$(cat /etc/glversion)
+	    case $$GL_VERSION in
+	        4.*)
+	            echo Version $$GL_VERSION is not supported
+	            exit 1
+	            ;;
+	        3.215)
+	            echo Version $$GL_VERSION is supported
+	            CHECK_MCUVERSION
+	            exit 0
+	            ;;
+	        3.*)
+	            echo Version $$GL_VERSION is *probably* supported
+	            ABORT_GLVERSION
+	            ;;
+	        *)
+	            echo Unknown version $$GL_VERSION
+	            ABORT_GLVERSION
+	            ;;
+        esac
+        CHECK_MCUVERSION
 	else
 		ABORT_GLVERSION
 	fi
@@ -130,8 +144,8 @@ define Package/blue-merle/postrm
 	mv /usr/bin/switchaction.orig /usr/bin/switchaction
 	mv /usr/bin/switch_queue.orig /usr/bin/switch_queue
 
-	rm /tmp/sim_change_start
-	rm /tmp/sim_change_switch
+	rm -f /tmp/sim_change_start
+	rm -f /tmp/sim_change_switch
 endef
 $(eval $(call BuildPackage,$(PKG_NAME)))
 
diff --git a/files/lib/blue-merle/imei_generate.py b/files/lib/blue-merle/imei_generate.py
index 4fd7cfe..59db66c 100644
--- a/files/lib/blue-merle/imei_generate.py
+++ b/files/lib/blue-merle/imei_generate.py
@@ -141,6 +141,10 @@ def generate_imei(imei_prefix, imsi_d):
 
 
 def validate_imei(imei):
+    # before anything check if length is 14 characters
+    if len(imei) != 14:
+        print(f"NOT A VALID IMEI: {imei} - IMEI must be 14 characters in length")
+        return False
     # cut off last digit
     validation_digit = int(imei[-1])
     imei_verify = imei[0:14]