diff --git a/modflash/Makefile b/modflash/Makefile
index bc758ff..5de6bc0 100644
--- a/modflash/Makefile
+++ b/modflash/Makefile
@@ -3,13 +3,13 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 #
 # Supported environments:
-#   * GNU/Linux
-#   * Windows NT (using MinGW/MSYS/Cygwin/WSL)
+#   * GNU on Linux, FreeBSD etc.
+#   * GNU on Windows NT (using MinGW/MSYS/Cygwin/WSL)
 
 include ../sdk/common.mk
 
 .PHONY: all
-all: | FLASHempty.ZX1 $(ADDITEM) ./addroms.sh ./addcores.sh roms.txt cores.txt
+all: | FLASHempty.ZX1 ./addroms.sh ./addcores.sh roms.txt cores.txt
 	cp FLASHempty.ZX1 FLASH.ZX1
 	./addroms.sh
 	./addcores.sh
diff --git a/modflash/addcores.sh b/modflash/addcores.sh
index c498228..7470749 100755
--- a/modflash/addcores.sh
+++ b/modflash/addcores.sh
@@ -7,24 +7,26 @@
 
 i=2
 
-Error() {
-	echo "ERROR: Exit status $1. Stopped." >&2
-	exit $1
-}
-
 AddCore() {
 	local f=${3%.*}.tap
 	echo "Adding core $i: \"$2\" ($3)..."
-	GenRom $1 "$2" $3 $f || Error $?
-	AddItem CORE$i $f || Error $?
+	GenRom $1 "$2" $3 $f
+	AddItem CORE$i $f
 	rm -f $f
 	let i+=1
 }
 
+OnError() {
+	local err=$?
+	echo "ERROR: Exit status $err. Stopped." >&2
+	exit $err
+}
+
 OnExit() {
         rm -f addcores.tmp
 }
 
+trap OnError ERR
 trap OnExit EXIT
 
 awk -F \; '/^[^#]+/{print "AddCore " $1 " " $2 " " gensub(/\\/, "/", "g", $3)}' cores.txt >addcores.tmp
diff --git a/modflash/addroms.sh b/modflash/addroms.sh
index 004e553..abf6873 100755
--- a/modflash/addroms.sh
+++ b/modflash/addroms.sh
@@ -7,26 +7,28 @@
 
 i=0
 
-Error() {
-	echo "ERROR: Exit status $1. Stopped." >&2
-	exit $1
-}
-
 AddROM() {
 	local n=`stat --printf "%s" $3`
 	local i1=$((i+n/16384-1))
 	local f=${3%.*}.tap
 	echo "Adding ROM in slots $i-$i1: \"$2\" ($3)..."
-	GenRom $1 "$2" $3 $f || Error $?
-	AddItem ROM $i $f || Error $?
+	GenRom $1 "$2" $3 $f
+	AddItem ROM $i $f
 	rm -f $f
 	let i=i1+1
 }
 
+OnError() {
+	local err=$?
+	echo "ERROR: Exit status $err. Stopped." >&2
+	exit $err
+}
+
 OnExit() {
 	rm -f addroms.tmp
 }
 
+trap OnError ERR
 trap OnExit EXIT
 
 awk -F \; '/^[^#]+/{print "AddROM " $1 " " $2 " " gensub(/\\/, "/", "g", $3)}' roms.txt >addroms.tmp