diff --git a/headers/posix/unistd.h b/headers/posix/unistd.h
index 2c3191d35d..585a8b61e5 100644
--- a/headers/posix/unistd.h
+++ b/headers/posix/unistd.h
@@ -129,7 +129,7 @@ extern int		tcsetpgrp(int fd, pid_t pgrpid);
 extern void		*sbrk(long incr);
 
 extern unsigned	int	alarm(unsigned int seconds);
-extern useconds_t	ualarm(unsigned int microSeconds, unsigned int interval);
+extern useconds_t	ualarm(useconds_t microSeconds, useconds_t interval);
 extern unsigned int	sleep(unsigned int seconds);
 extern int			usleep(unsigned int microSeconds);
 extern clock_t		clock(void);
diff --git a/src/system/libroot/posix/unistd/ualarm.c b/src/system/libroot/posix/unistd/ualarm.c
index 6331323c28..927827ac6b 100644
--- a/src/system/libroot/posix/unistd/ualarm.c
+++ b/src/system/libroot/posix/unistd/ualarm.c
@@ -1,7 +1,7 @@
 /*
-** Copyright 2004, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
-** Distributed under the terms of the Haiku License.
-*/
+ * Copyright 2004-2005, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
 
 
 #include <errno.h>
@@ -11,15 +11,15 @@
 #include <syscalls.h>
 
 
-uint
-ualarm(uint usec, uint interval)
+useconds_t
+ualarm(useconds_t usec, useconds_t interval)
 {
 	struct itimerval value, oldValue;
 
-	value.it_value.tv_sec = 0;
-	value.it_value.tv_usec = usec;
-	value.it_interval.tv_sec = 0;
-	value.it_interval.tv_usec = interval;
+	value.it_value.tv_sec = usec / 1000000;
+	value.it_value.tv_usec = usec % 1000000;
+	value.it_interval.tv_sec = interval / 1000000;
+	value.it_interval.tv_usec = interval % 1000000;
 
 	if (setitimer(ITIMER_REAL, &value, &oldValue) < 0)
 		return -1;