diff --git a/library/include/unistd.h b/library/include/unistd.h
index a167bbd..7b9101a 100644
--- a/library/include/unistd.h
+++ b/library/include/unistd.h
@@ -117,7 +117,7 @@ extern int readlink(const char * path_name, char * buffer, int buffer_size);
 extern int chdir(const char * path_name);
 extern int lockf(int file_descriptor, int function, off_t size);
 extern unsigned int sleep(unsigned int seconds);
-extern void usleep(unsigned long microseconds);
+extern int usleep(unsigned long microseconds);
 extern int getopt(int argc, char * const argv[], const char *opts);
 extern pid_t getpid(void);
 extern char *realpath(const char *file_name, char *resolved_name);
diff --git a/library/unistd_usleep.c b/library/unistd_usleep.c
index 9025378..235c33d 100644
--- a/library/unistd_usleep.c
+++ b/library/unistd_usleep.c
@@ -41,7 +41,7 @@
 
 /****************************************************************************/
 
-void
+int
 usleep(unsigned long microseconds)
 {
 	ENTER();
@@ -51,4 +51,6 @@ usleep(unsigned long microseconds)
 	__time_delay(0,microseconds);
 
 	LEAVE();
+	
+	return 0;
 }