diff --git a/src/add-ons/kernel/busses/ata/ide_isa/ide_isa.c b/src/add-ons/kernel/busses/ata/ide_isa/ide_isa.c
index 591d764580..80e1d405da 100644
--- a/src/add-ons/kernel/busses/ata/ide_isa/ide_isa.c
+++ b/src/add-ons/kernel/busses/ata/ide_isa/ide_isa.c
@@ -409,7 +409,7 @@ channel_removed(void *cookie)
 	TRACE("channel_removed()\n");
 
 	// disable access instantly
-	atomic_or(&channel->lost, 1);
+	atomic_or((int32*)&channel->lost, 1);
 }
 
 
diff --git a/src/add-ons/kernel/drivers/disk/floppy/pc_floppy/floppy.c b/src/add-ons/kernel/drivers/disk/floppy/pc_floppy/floppy.c
index b78cda248d..90e29d2188 100644
--- a/src/add-ons/kernel/drivers/disk/floppy/pc_floppy/floppy.c
+++ b/src/add-ons/kernel/drivers/disk/floppy/pc_floppy/floppy.c
@@ -545,7 +545,7 @@ motor_off_daemon(void *t, int tim)
 	for (i = 0; i < MAX_FLOPPIES; i++) {
 		if (floppies[i].iobase && !floppies[i].pending_cmd && floppies[i].motor_timeout > 0) {
 			TRACE("floppies[%d].motor_timeout = %ld\n", i, floppies[i].motor_timeout);
-			if (atomic_add(&floppies[i].motor_timeout, -500000) <= 500000) {
+			if (atomic_add((int32*)&floppies[i].motor_timeout, -500000) <= 500000) {
 				dprintf("turning off motor for drive %d\n", floppies[i].drive_num);
 				turn_off_motor(&floppies[i]);
 				floppies[i].motor_timeout = 0;