diff --git a/Userspace/libc/include/bits/libc.h b/Userspace/libc/include/bits/libc.h
index b2e95ccc..4c0d0bd2 100644
--- a/Userspace/libc/include/bits/libc.h
+++ b/Userspace/libc/include/bits/libc.h
@@ -66,5 +66,9 @@ int sysdep(LStat)(const char *Pathname, struct stat *Statbuf);
 int sysdep(Truncate)(const char *Pathname, off_t Length);
 int sysdep(MakeDirectory)(const char *Pathname, mode_t Mode);
 int sysdep(ProcessControl)(unsigned long Option, unsigned long Arg1, unsigned long Arg2, unsigned long Arg3, unsigned long Arg4);
+int sysdep(ChangeDirectory)(const char *Pathname);
+char *sysdep(GetWorkingDirectory)(char *Buffer, size_t Size);
+int sysdep(Brk)(void *Address);
+int sysdep(FileControl)(int Descriptor, int Command, void *Arg);
 
 #endif // FENNIX_BITS_LIBC_H
diff --git a/Userspace/libc/include/unistd.h b/Userspace/libc/include/unistd.h
index 2b3af1e7..0ce82788 100644
--- a/Userspace/libc/include/unistd.h
+++ b/Userspace/libc/include/unistd.h
@@ -61,8 +61,8 @@ extern "C"
 
 	int access(const char *path, int amode);
 	unsigned int alarm(unsigned int seconds);
-	int brk(void *);
-	int chdir(const char *);
+	int brk(void *addr);
+	int chdir(const char *path);
 	int chroot(const char *);
 	int chown(const char *, uid_t, gid_t);
 	int close(int fildes);
@@ -87,7 +87,7 @@ extern "C"
 	long int fpathconf(int, int);
 	int fsync(int);
 	int ftruncate(int, off_t);
-	char *getcwd(char *, size_t);
+	char *getcwd(char *buf, size_t size);
 	int getdtablesize(void);
 	gid_t getegid(void);
 	uid_t geteuid(void);
@@ -122,7 +122,7 @@ extern "C"
 	ssize_t read(int fildes, void *buf, size_t nbyte);
 	int readlink(const char *, char *, size_t);
 	int rmdir(const char *);
-	void *sbrk(intptr_t);
+	void *sbrk(intptr_t incr);
 	int setgid(gid_t);
 	int setpgid(pid_t, pid_t);
 	pid_t setpgrp(void);
diff --git a/Userspace/libc/src/std/fcntl.c b/Userspace/libc/src/std/fcntl.c
index e99278ae..0797a627 100644
--- a/Userspace/libc/src/std/fcntl.c
+++ b/Userspace/libc/src/std/fcntl.c
@@ -25,7 +25,14 @@
 
 export int creat(const char *path, mode_t mode) { return open(path, O_WRONLY | O_CREAT | O_TRUNC, mode); }
 
-export int fcntl(int fildes, int cmd, ...);
+export int fcntl(int fildes, int cmd, ...)
+{
+	va_list args;
+	va_start(args, cmd);
+	void *arg = va_arg(args, void *);
+	va_end(args);
+	return __check_errno(sysdep(FileControl)(fildes, cmd, arg), -1);
+}
 
 export int open(const char *path, int oflag, ...)
 {
diff --git a/Userspace/libc/src/std/unistd.c b/Userspace/libc/src/std/unistd.c
index 06563a7a..a7682d43 100644
--- a/Userspace/libc/src/std/unistd.c
+++ b/Userspace/libc/src/std/unistd.c
@@ -40,8 +40,16 @@ export unsigned int alarm(unsigned int seconds)
 	return __check_errno(-ENOSYS, -1);
 }
 
-export int brk(void *);
-export int chdir(const char *);
+export int brk(void *addr)
+{
+	return __check_errno(sysdep(Brk)(addr), -1);
+}
+
+export int chdir(const char *path)
+{
+	return __check_errno(sysdep(ChangeDirectory)(path), -1);
+}
+
 export int chroot(const char *);
 export int chown(const char *, uid_t, gid_t);
 
@@ -176,7 +184,12 @@ export pid_t fork(void)
 export long int fpathconf(int, int);
 export int fsync(int);
 export int ftruncate(int, off_t);
-export char *getcwd(char *, size_t);
+
+export char *getcwd(char *buf, size_t size)
+{
+	return (char *)__check_errno((__iptr)sysdep(GetWorkingDirectory)(buf, size), (__iptr)NULL);
+}
+
 export int getdtablesize(void);
 export gid_t getegid(void);
 export uid_t geteuid(void);
@@ -281,7 +294,7 @@ export ssize_t read(int fildes, void *buf, size_t nbyte)
 
 export int readlink(const char *, char *, size_t);
 export int rmdir(const char *);
-export void *sbrk(intptr_t);
+export void *sbrk(intptr_t incr);
 export int setgid(gid_t);
 export int setpgid(pid_t, pid_t);
 export pid_t setpgrp(void);
diff --git a/Userspace/libc/sysdeps/fennix/generic/syscalls.c b/Userspace/libc/sysdeps/fennix/generic/syscalls.c
index cf03d41a..6d57d26a 100644
--- a/Userspace/libc/sysdeps/fennix/generic/syscalls.c
+++ b/Userspace/libc/sysdeps/fennix/generic/syscalls.c
@@ -189,3 +189,23 @@ int sysdep(ProcessControl)(unsigned long Option, unsigned long Arg1, unsigned lo
 {
 	return call_prctl(Option, Arg1, Arg2, Arg3, Arg4);
 }
+
+int sysdep(ChangeDirectory)(const char *Pathname)
+{
+	return call_chdir(Pathname);
+}
+
+char *sysdep(GetWorkingDirectory)(char *Buffer, size_t Size)
+{
+	return (char *)call_getcwd(Buffer, Size);
+}
+
+int sysdep(Brk)(void *Address)
+{
+	return call_brk(Address);
+}
+
+int sysdep(FileControl)(int Descriptor, int Command, void *Arg)
+{
+	return call_fcntl(Descriptor, Command, Arg);
+}