diff --git a/tool/run/boot_dir/hw b/tool/run/boot_dir/hw
index 40ca97d302..bb8b31f1d2 100644
--- a/tool/run/boot_dir/hw
+++ b/tool/run/boot_dir/hw
@@ -107,7 +107,7 @@ proc run_boot_dir {binaries} {
 		#
 		# Compress Genode image, to be uncompressed by GRUB
 		#
-		exec gzip [run_dir]/boot/image.elf
+		exec gzip -n [run_dir]/boot/image.elf
 
 		if {[have_include "image/disk"]} {
 			install_disk_bootloader_to_run_dir
diff --git a/tool/run/boot_dir/nova b/tool/run/boot_dir/nova
index d41f6bbbf7..d0cf746ed2 100644
--- a/tool/run/boot_dir/nova
+++ b/tool/run/boot_dir/nova
@@ -103,7 +103,7 @@ proc run_boot_dir {binaries} {
 		#
 		# Compress Genode image, to be uncompressed by GRUB
 		#
-		exec gzip [run_dir]/boot/image.elf
+		exec gzip -n [run_dir]/boot/image.elf
 
 		if {[have_include "image/disk"]} {
 			install_disk_bootloader_to_run_dir