diff --git a/target/linux/ramips/dts/mt7621_iptime_ax2004m.dts b/target/linux/ramips/dts/mt7621_iptime_ax2004m.dts
index 51be0d4939..7237bf822f 100644
--- a/target/linux/ramips/dts/mt7621_iptime_ax2004m.dts
+++ b/target/linux/ramips/dts/mt7621_iptime_ax2004m.dts
@@ -57,6 +57,11 @@
 &nand {
 	status = "okay";
 
+	mediatek,nmbm;
+	mediatek,bmt-max-ratio = <1>;
+	mediatek,bmt-max-reserved-blocks = <64>;
+	mediatek,bmt-remap-range = <0x000000 0x580000>;
+
 	partitions {
 		compatible = "fixed-partitions";
 		#address-cells = <1>;
@@ -118,6 +123,8 @@
 				reg = <0x400000 0x7280000>;
 			};
 		};
+
+		/* last 8 MiB is reserved for NMBM bad block table */
 	};
 };
 
diff --git a/target/linux/ramips/image/mt7621.mk b/target/linux/ramips/image/mt7621.mk
index ab1b829ba0..7b7266b73e 100644
--- a/target/linux/ramips/image/mt7621.mk
+++ b/target/linux/ramips/image/mt7621.mk
@@ -1461,6 +1461,10 @@ define Device/iptime_ax2004m
   DEVICE_VENDOR := ipTIME
   DEVICE_MODEL := AX2004M
   DEVICE_PACKAGES := kmod-mt7915-firmware kmod-usb3 -uboot-envtools
+  DEVICE_COMPAT_VERSION := 2.0
+  DEVICE_COMPAT_MESSAGE := NMBM has been newly enabled, and its flash block \
+	mapping might be incompatible with existing installation. \
+	New installation via recovery mode is recommended.
 endef
 TARGET_DEVICES += iptime_ax2004m
 
diff --git a/target/linux/ramips/mt7621/base-files/etc/board.d/05_compat-version b/target/linux/ramips/mt7621/base-files/etc/board.d/05_compat-version
index 45bef9385b..c510dfd81a 100644
--- a/target/linux/ramips/mt7621/base-files/etc/board.d/05_compat-version
+++ b/target/linux/ramips/mt7621/base-files/etc/board.d/05_compat-version
@@ -8,6 +8,9 @@
 board_config_update
 
 case "$(board_name)" in
+	iptime,ax2004m)
+		ucidef_set_compat_version "2.0"
+		;;
 	*)
 		ucidef_set_compat_version "1.1"
 		;;