diff --git a/Cargo.toml b/Cargo.toml
index 6766a5b2c..1eac83ac3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,6 +17,7 @@ ethcore-util = { path = "util" }
 ethcore = { path = "ethcore" }
 ethsync = { path = "sync" }
 ethcore-rpc = { path = "rpc", optional = true }
+fdlimit = { path = "util/fdlimit" }
 
 [features]
 default = ["rpc"]
diff --git a/parity/main.rs b/parity/main.rs
index 7d0a08855..2aa0f7070 100644
--- a/parity/main.rs
+++ b/parity/main.rs
@@ -28,6 +28,7 @@ extern crate ethsync;
 extern crate log as rlog;
 extern crate env_logger;
 extern crate ctrlc;
+extern crate fdlimit;
 
 #[cfg(feature = "rpc")]
 extern crate ethcore_rpc as rpc;
@@ -95,6 +96,7 @@ fn main() {
 	let args: Args = Args::docopt().decode().unwrap_or_else(|e| e.exit());
 
 	setup_log(&args.flag_logging);
+	unsafe { ::fdlimit::raise_fd_limit(); }
 
 	let spec = ethereum::new_frontier();
 	let init_nodes = match args.arg_enode.len() {
diff --git a/util/fdlimit/Cargo.toml b/util/fdlimit/Cargo.toml
new file mode 100644
index 000000000..42aa582fe
--- /dev/null
+++ b/util/fdlimit/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+description = "Utility function to raise file descriptor limit on OS X"
+homepage = "http://ethcore.io"
+license = "GPL-3.0"
+name = "fdlimit"
+version = "0.1.0"
+authors = ["Ethcore <admin@ethcore.io>"]
+
+[dependencies]
+libc = "0.2"
diff --git a/util/fdlimit/src/lib.rs b/util/fdlimit/src/lib.rs
new file mode 100644
index 000000000..e659bb8c9
--- /dev/null
+++ b/util/fdlimit/src/lib.rs
@@ -0,0 +1,18 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+// 
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// Parity 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 General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.extern crate libc;
+extern crate libc;
+pub mod raise_fd_limit;
+pub use raise_fd_limit::raise_fd_limit;
diff --git a/util/fdlimit/src/raise_fd_limit.rs b/util/fdlimit/src/raise_fd_limit.rs
new file mode 100644
index 000000000..f57ac2785
--- /dev/null
+++ b/util/fdlimit/src/raise_fd_limit.rs
@@ -0,0 +1,61 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+/// darwin_fd_limit exists to work around an issue where launchctl on Mac OS X
+/// defaults the rlimit maxfiles to 256/unlimited. The default soft limit of 256
+/// ends up being far too low for our multithreaded scheduler testing, depending
+/// on the number of cores available.
+///
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+#[allow(non_camel_case_types)]
+pub unsafe fn raise_fd_limit() {
+    use libc;
+    use std::cmp;
+    use std::io;
+    use std::mem::size_of_val;
+    use std::ptr::null_mut;
+
+    static CTL_KERN: libc::c_int = 1;
+    static KERN_MAXFILESPERPROC: libc::c_int = 29;
+
+    // The strategy here is to fetch the current resource limits, read the
+    // kern.maxfilesperproc sysctl value, and bump the soft resource limit for
+    // maxfiles up to the sysctl value.
+
+    // Fetch the kern.maxfilesperproc value
+    let mut mib: [libc::c_int; 2] = [CTL_KERN, KERN_MAXFILESPERPROC];
+    let mut maxfiles: libc::c_int = 0;
+    let mut size: libc::size_t = size_of_val(&maxfiles) as libc::size_t;
+    if libc::sysctl(&mut mib[0], 2, &mut maxfiles as *mut _ as *mut _, &mut size,
+              null_mut(), 0) != 0 {
+        let err = io::Error::last_os_error();
+        panic!("raise_fd_limit: error calling sysctl: {}", err);
+    }
+
+    // Fetch the current resource limits
+    let mut rlim = libc::rlimit{rlim_cur: 0, rlim_max: 0};
+    if libc::getrlimit(libc::RLIMIT_NOFILE, &mut rlim) != 0 {
+        let err = io::Error::last_os_error();
+        panic!("raise_fd_limit: error calling getrlimit: {}", err);
+    }
+
+    // Bump the soft limit to the smaller of kern.maxfilesperproc and the hard
+    // limit
+    rlim.rlim_cur = cmp::min(maxfiles as libc::rlim_t, rlim.rlim_max);
+
+    // Set our newly-increased resource limit
+    if libc::setrlimit(libc::RLIMIT_NOFILE, &rlim) != 0 {
+        let err = io::Error::last_os_error();
+        panic!("raise_fd_limit: error calling setrlimit: {}", err);
+    }
+}
+
+#[cfg(not(any(target_os = "macos", target_os = "ios")))]
+pub unsafe fn raise_fd_limit() {}