diff --git a/minimal-payload-ram/Makefile b/minimal-payload-ram/Makefile
index 285e1e9..3637010 100644
--- a/minimal-payload-ram/Makefile
+++ b/minimal-payload-ram/Makefile
@@ -13,7 +13,7 @@ all: main.uf2
 main.elf: startup.o main.o
 
 %.uf2: %.bin
-	~/code/uf2/utils/uf2conv.py -c -f 0xdeadbeef -b 0x20000000 -o $@.temp $<
+	~/code/uf2/utils/uf2conv.py -c -f 0x699b62ec -b 0x20000000 -o $@.temp $<
 	xxd $@.temp | sed 's/5546 320a 5751 5d9e 0020 0000/5546 320a 5751 5d9e 0120 0000/g' | xxd -r >$@
 
 %.bin: %.elf
diff --git a/minimal-payload/Makefile b/minimal-payload/Makefile
index 5f14df9..df7746e 100644
--- a/minimal-payload/Makefile
+++ b/minimal-payload/Makefile
@@ -13,7 +13,7 @@ all: main.uf2
 main.elf: startup.o main.o
 
 %.uf2: %.bin
-	~/code/uf2/utils/uf2conv.py -c -f 0xdeadbeef -b 0x08001000 -o $@ $<
+	~/code/uf2/utils/uf2conv.py -c -f 0x699b62ec -b 0x08001000 -o $@ $<
 
 %.bin: %.elf
 	$(OBJCOPY) -O binary $< $@