diff --git a/features.in/arm-rpi4/image-scripts.d/98-bootstrap-boot-by-firmware b/features.in/arm-rpi4/image-scripts.d/98-bootstrap-boot-by-firmware
index 4b5bdcef..cf18d5bd 100755
--- a/features.in/arm-rpi4/image-scripts.d/98-bootstrap-boot-by-firmware
+++ b/features.in/arm-rpi4/image-scripts.d/98-bootstrap-boot-by-firmware
@@ -37,7 +37,7 @@ dtoverlay=vc4-fkms-v3d
 EOF
 
 [ "$GLOBAL_ARCH" = armh ] && \
-	sed -i 's/.bin/-32b.bin/g' /boot/efi/config.txt
+	sed -i 's/.bin/_32b.bin/g' /boot/efi/config.txt
 
 # Enable bootloading without u-boot
 sh -x rpi4-boot-nouboot $kflavour