diff --git a/src/kernel/libroot/posix/unistd/ttyname.c b/src/kernel/libroot/posix/unistd/ttyname.c
index 1b94450f02..5efe6d1125 100644
--- a/src/kernel/libroot/posix/unistd/ttyname.c
+++ b/src/kernel/libroot/posix/unistd/ttyname.c
@@ -3,6 +3,9 @@
 ** Distributed under the terms of the OpenBeOS License.
 */
 
+
+#include <SupportDefs.h>
+
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -15,66 +18,61 @@
 #define DEV_TTY  "/dev/tt/"
 
 
-/*
- * ttyname - return the full pathname of the tty device
- *           (NULL if not a tty or an error occurs)
+/** return the full pathname of the tty device
+ *	(NULL if not a tty or an error occurs)
  */
+
 char *
-ttyname (int fd)
+ttyname(int fd)
 {
 	static char pathname[MAXPATHLEN];
-	
 	char  *stub = pathname + sizeof(DEV_TTY) - 1;
 	int   stubLen = sizeof(pathname) - sizeof(DEV_TTY);
-	
 	struct stat fdStat;
 	DIR   *dir;
 	bool  found = false;
-	
-	
+
 	// first, some sanity checks:
 	if (!isatty(fd))
 		return NULL;
-	
+
 	if (fstat(fd, &fdStat) < 0)
 		return NULL;
-	
+
 	if (!S_ISCHR(fdStat.st_mode))
 		return NULL;
-	
-	
+
 	// start with the root tty directory at /dev
 	strcpy(pathname, DEV_TTY);
-	
+
 	if ((dir = opendir(pathname)) != NULL) {
 		// find a matching entry in the directory:
 		//   we must match both the inode for the file 
 		//   and the device that the file resides on
-		
 		struct dirent *e;
 		struct stat entryStat;
-		
+
 		while ((e = readdir(dir)) != NULL) {
 			// try to match the file's inode
 			if (e->d_ino != fdStat.st_ino)
 				continue;
-			
+
 			// construct the entry's full filename and
 			// call stat() to retrieve the inode info
 			strncpy(stub, e->d_name, stubLen);
-			
+
 			if (stat(pathname, &entryStat) < 0)
 				continue;
-			
+
 			if (entryStat.st_ino == fdStat.st_ino &&
 			    entryStat.st_dev == fdStat.st_dev) {
 			    found = true;
 			    break;
 			}
 		}
-	
+
 		closedir(dir);
 	}
-	
+
 	return found ? pathname : NULL;
 }