diff --git a/test-app/Makefile b/test-app/Makefile
index 5cea7e1ef..e0bca642c 100644
--- a/test-app/Makefile
+++ b/test-app/Makefile
@@ -8,7 +8,8 @@ ARCH?=ARM
 MCUXPRESSO_CMSIS?=$(MCUXPRESSO)/CMSIS
 CFLAGS+=-I.
 CFLAGS+=-I./wcs
-DEBUG=1
+DEBUG?=1
+DELTA_DATA_SIZE?=2000
 
 ifeq ($(SIGN),RSA2048)
   IMAGE_HEADER_SIZE:=512
@@ -166,7 +167,7 @@ endif
 ifeq ($(TARGET),sim)
   APP_OBJS=app_$(TARGET).o ../test-app/libwolfboot.o ../hal/$(TARGET).o
   # Override linker flags
-  LDFLAGS=
+  LDFLAGS=-Wl,-Map=image.map
 endif
 
 ifeq ($(EXT_FLASH),1)
@@ -327,6 +328,9 @@ CFLAGS+=-I../lib/wolfssl
 standalone:CFLAGS+=-D"TEST_APP_STANDALONE"
 standalone:LDFLAGS:=-T standalone.ld -Wl,-gc-sections -Wl,-Map=image.map
 
+delta-extra-data:CFLAGS+=-D"TEST_DELTA_DATA=$(DELTA_DATA_SIZE)" -ffunction-sections -fdata-sections
+delta-extra-data:LDFLAGS=-Wl,-Map=image.map
+
 image.bin: image.elf
 	@echo "\t[BIN] $@"
 	$(Q)$(OBJCOPY) --gap-fill $(FILL_BYTE) -O binary $^ $@
@@ -338,6 +342,8 @@ image.elf: $(APP_OBJS) $(LSCRIPT)
 
 standalone: image.bin
 
+delta-extra-data: image.bin
+
 ../test-app/libwolfboot.o: ../src/libwolfboot.c FORCE
 	@echo "\t[CC-$(ARCH)] $@"
 	$(Q)$(CC) $(CFLAGS) -c $(OUTPUT_FLAG) $@ ../src/libwolfboot.c
diff --git a/test-app/app_sim.c b/test-app/app_sim.c
index b977daabd..e200db557 100644
--- a/test-app/app_sim.c
+++ b/test-app/app_sim.c
@@ -40,6 +40,11 @@
 char enc_key[] = "0123456789abcdef0123456789abcdef"
 		 "0123456789abcdef";
 
+#ifdef TEST_DELTA_DATA
+static volatile char __attribute__((used)) garbage[TEST_DELTA_DATA] = {0x01, 0x02, 0x03, 0x04 };
+
+#endif
+
 void hal_init(void);
 
 int do_cmd(const char *cmd)
diff --git a/tools/test.mk b/tools/test.mk
index eb5ecd7ec..fadf552f3 100644
--- a/tools/test.mk
+++ b/tools/test.mk
@@ -7,6 +7,7 @@ SPI_CHIP=SST25VF080B
 SPI_OPTIONS=SPI_FLASH=1 WOLFBOOT_PARTITION_SIZE=0x80000 WOLFBOOT_PARTITION_UPDATE_ADDRESS=0x00000 WOLFBOOT_PARTITION_SWAP_ADDRESS=0x80000
 SIGN_ARGS=
 SIGN_ENC_ARGS=
+DELTA_DATA_SIZE?=2000
 
 # python version only supported using
 # KEYGEN_TOOL="python3 $(WOLFBOOT_ROOT)/tools/keytools/keygen.py"
@@ -159,6 +160,28 @@ test-sim-external-flash-with-update: wolfboot.bin test-app/image.elf FORCE
 	$(Q)$(BINASSEMBLE) external_flash.dd 0 test-app/image_v$(TEST_UPDATE_VERSION)_signed.bin \
 		$(WOLFBOOT_PARTITION_SIZE) erased_sec.dd
 
+test-sim-external-flash-with-enc-delta-update-extradata:DELTA_UPDATE_OPTIONS=--delta test-app/image_v1_signed.bin
+test-sim-external-flash-with-enc-delta-update-extradata:SIGN_ENC_ARGS=--encrypt /tmp/enc_key.der --aes128
+test-sim-external-flash-with-enc-delta-update-extradata: wolfboot.bin test-app/image.elf FORCE
+	@printf "0123456789abcdef0123456789abcdef0123456789abcdef" > /tmp/enc_key.der
+	$(Q)$(SIGN_TOOL) $(SIGN_OPTIONS) test-app/image.elf $(PRIVATE_KEY) 1
+	$(Q)cp test-app/image_v1_signed.bin test-app/image_v1_signed.bak
+	$(Q)rm -f test-app/image.elf test-app/app_sim.o
+	$(Q)make -C test-app delta-extra-data DELTA_DATA_SIZE=$(DELTA_DATA_SIZE)
+	$(Q)cp test-app/image_v1_signed.bak test-app/image_v1_signed.bin
+	$(Q)$(SIGN_TOOL) $(SIGN_OPTIONS) $(SIGN_ENC_ARGS) test-app/image.elf $(PRIVATE_KEY) $(TEST_UPDATE_VERSION)
+	$(Q)$(SIGN_TOOL) $(SIGN_ARGS) $(DELTA_UPDATE_OPTIONS) $(SIGN_ENC_ARGS) \
+		test-app/image.elf $(PRIVATE_KEY) $(TEST_UPDATE_VERSION)
+	$(Q)dd if=/dev/zero bs=$$(($(WOLFBOOT_PARTITION_SIZE))) count=1 2>/dev/null | tr "\000" "\377" > v1_part.dd
+	$(Q)dd if=test-app/image_v1_signed.bin bs=256 of=v1_part.dd conv=notrunc
+	$(Q)$(BINASSEMBLE) internal_flash.dd \
+		0 wolfboot.bin \
+		$$(($(WOLFBOOT_PARTITION_BOOT_ADDRESS) - $(ARCH_FLASH_OFFSET))) v1_part.dd
+	$(Q)dd if=/dev/zero bs=$$(($(WOLFBOOT_SECTOR_SIZE))) count=1 2>/dev/null | tr "\000" "\377" > erased_sec.dd
+	$(Q)$(BINASSEMBLE) external_flash.dd 0 test-app/image_v$(TEST_UPDATE_VERSION)_signed_diff_encrypted.bin \
+		$(WOLFBOOT_PARTITION_SIZE) erased_sec.dd
+	$(Q)ls -l test-app/*.bin
+
 
 test-sim-external-flash-with-enc-update:SIGN_ENC_ARGS=--encrypt /tmp/enc_key.der --aes128
 test-sim-external-flash-with-enc-update: wolfboot.bin test-app/image.elf FORCE