diff --git a/src/client/Client.cc b/src/client/Client.cc
index 6286996cc53..a718a0cad66 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -4188,6 +4188,19 @@ int Client::chmod(const char *relpath, mode_t mode)
   return _setattr(in, &attr, CEPH_SETATTR_MODE);
 }
 
+int Client::fchmod(int fd, mode_t mode)
+{
+  Mutex::Locker lock(client_lock);
+  tout(cct) << "fchmod" << std::endl;
+  tout(cct) << fd << std::endl;
+  tout(cct) << mode << std::endl;
+  assert(fd_map.count(fd));
+  Fh *f = fd_map[fd];
+  struct stat attr;
+  attr.st_mode = mode;
+  return _setattr(f->inode, &attr, CEPH_SETATTR_MODE);
+}
+
 int Client::chown(const char *relpath, uid_t uid, gid_t gid)
 {
   Mutex::Locker lock(client_lock);
diff --git a/src/client/Client.h b/src/client/Client.h
index 404096bceed..d4f61d6ed0a 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -588,6 +588,7 @@ public:
 
   int setattr(const char *relpath, struct stat *attr, int mask);
   int chmod(const char *path, mode_t mode);
+  int fchmod(int fd, mode_t mode);
   int chown(const char *path, uid_t uid, gid_t gid);
   int utime(const char *path, struct utimbuf *buf);
   int truncate(const char *path, loff_t size);
diff --git a/src/include/cephfs/libcephfs.h b/src/include/cephfs/libcephfs.h
index 937c192b22f..e0048b9e692 100644
--- a/src/include/cephfs/libcephfs.h
+++ b/src/include/cephfs/libcephfs.h
@@ -462,6 +462,7 @@ int ceph_lstat(struct ceph_mount_info *cmount, const char *path, struct stat *st
  * @returns 0 on success or negative error code on failure.
  */
 int ceph_setattr(struct ceph_mount_info *cmount, const char *relpath, struct stat *attr, int mask);
+
 /**
  * Change the mode bits (permissions) of a file/directory.
  *
@@ -472,6 +473,16 @@ int ceph_setattr(struct ceph_mount_info *cmount, const char *relpath, struct sta
  */
 int ceph_chmod(struct ceph_mount_info *cmount, const char *path, mode_t mode);
 
+/**
+ * Change the mode bits (permissions) of an open file.
+ *
+ * @param cmount the ceph mount handle to use for performing the chmod.
+ * @param fd the open file descriptor to change the mode bits on.
+ * @param mode the new permissions to set.
+ * @returns 0 on success or a negative error code on failure.
+ */
+int ceph_fchmod(struct ceph_mount_info *cmount, int fd, mode_t mode);
+
 /**
  * Change the ownership of a file/directory.
  * 
diff --git a/src/libcephfs.cc b/src/libcephfs.cc
index f4e4ad0b03e..8e1020e85e0 100644
--- a/src/libcephfs.cc
+++ b/src/libcephfs.cc
@@ -450,6 +450,10 @@ extern "C" int ceph_chmod(struct ceph_mount_info *cmount, const char *path, mode
 {
   return cmount->get_client()->chmod(path, mode);
 }
+extern "C" int ceph_fchmod(struct ceph_mount_info *cmount, int fd, mode_t mode)
+{
+  return cmount->get_client()->fchmod(fd, mode);
+}
 extern "C" int ceph_chown(struct ceph_mount_info *cmount, const char *path,
 			  uid_t uid, gid_t gid)
 {