diff --git a/libc/Makefile b/libc/Makefile
index f243c1ec..b7a538be 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -176,6 +176,7 @@ fsm_recv.o \
 fsm_send.o \
 fstatat.o \
 fstat.o \
+fsync.o \
 ftruncate.o \
 getc.o \
 getcwd.o \
diff --git a/libc/fsync.cpp b/libc/fsync.cpp
new file mode 100644
index 00000000..6f3972d4
--- /dev/null
+++ b/libc/fsync.cpp
@@ -0,0 +1,34 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    fsync.cpp
+    Open a file relative to directory.
+
+*******************************************************************************/
+
+#include <sys/syscall.h>
+
+#include <unistd.h>
+
+DEFN_SYSCALL1(int, sys_fsync, SYSCALL_FSYNC, int);
+
+extern "C" int fsync(int fd)
+{
+	return sys_fsync(fd);
+}
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 8a9d2715..ff7b84f8 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -93,7 +93,6 @@ void encrypt(char [64], int);
 int fdatasync(int);
 int fexecve(int, char* const [], char* const []);
 long fpathconf(int, int);
-int fsync(int);
 gid_t getegid(void);
 uid_t geteuid(void);
 gid_t getgid(void);
@@ -155,6 +154,7 @@ int faccessat(int, const char*, int, int);
 int fchdir(int);
 int fchown(int, uid_t, gid_t);
 int fchownat(int, const char*, uid_t, gid_t, int);
+int fsync(int);
 int ftruncate(int, off_t);
 char* getcwd(char*, size_t);
 char* get_current_dir_name(void);
diff --git a/sortix/include/sortix/syscallnum.h b/sortix/include/sortix/syscallnum.h
index 3f18848c..42e4a9c7 100644
--- a/sortix/include/sortix/syscallnum.h
+++ b/sortix/include/sortix/syscallnum.h
@@ -96,6 +96,7 @@
 #define SYSCALL_PPOLL 72
 #define SYSCALL_RENAMEAT 73
 #define SYSCALL_READLINKAT 74
-#define SYSCALL_MAX_NUM 75 /* index of highest constant + 1 */
+#define SYSCALL_FSYNC 75
+#define SYSCALL_MAX_NUM 76 /* index of highest constant + 1 */
 
 #endif
diff --git a/sortix/io.cpp b/sortix/io.cpp
index 58f6270d..96ee9067 100644
--- a/sortix/io.cpp
+++ b/sortix/io.cpp
@@ -559,6 +559,15 @@ static ssize_t sys_readlinkat(int dirfd, const char* path, char* buf, size_t siz
 	return (int) desc->readlink(&ctx, buf, size);
 }
 
+static int sys_fsync(int fd)
+{
+	Ref<Descriptor> desc = CurrentProcess()->GetDescriptor(fd);
+	if ( !desc )
+		return -1;
+	ioctx_t ctx; SetupUserIOCtx(&ctx);
+	return desc->sync(&ctx);
+}
+
 void Init()
 {
 	Syscall::Register(SYSCALL_ACCESS, (void*) sys_access);
@@ -577,6 +586,7 @@ void Init()
 	Syscall::Register(SYSCALL_FCNTL, (void*) sys_fcntl);
 	Syscall::Register(SYSCALL_FSTATAT, (void*) sys_fstatat);
 	Syscall::Register(SYSCALL_FSTAT, (void*) sys_fstat);
+	Syscall::Register(SYSCALL_FSYNC, (void*) sys_fsync);
 	Syscall::Register(SYSCALL_FTRUNCATE, (void*) sys_ftruncate);
 	Syscall::Register(SYSCALL_GETTERMMODE, (void*) sys_gettermmode);
 	Syscall::Register(SYSCALL_ISATTY, (void*) sys_isatty);