diff --git a/CI/install-dependencies-macos.sh b/CI/install-dependencies-macos.sh
index 4fc3e4f6..9945e4ff 100755
--- a/CI/install-dependencies-macos.sh
+++ b/CI/install-dependencies-macos.sh
@@ -8,7 +8,7 @@ brew install libav
 
 # qtwebsockets deps
 # qt latest
-brew install qt5
+brew install ./CI/macos/qt.rb
 
 # Packages app
 wget --quiet --retry-connrefused --waitretry=1 https://s3-us-west-2.amazonaws.com/obs-nightly/Packages.pkg
diff --git a/CI/macos/qt.rb b/CI/macos/qt.rb
new file mode 100644
index 00000000..71416153
--- /dev/null
+++ b/CI/macos/qt.rb
@@ -0,0 +1,157 @@
+# Patches for Qt must be at the very least submitted to Qt's Gerrit codereview
+# rather than their bug-report Jira. The latter is rarely reviewed by Qt.
+class Qt < Formula
+  desc "Cross-platform application and UI framework"
+  homepage "https://www.qt.io/"
+  url "https://download.qt.io/official_releases/qt/5.10/5.10.0/single/qt-everywhere-src-5.10.0.tar.xz"
+  mirror "https://www.mirrorservice.org/sites/download.qt-project.org/official_releases/qt/5.10/5.10.0/single/qt-everywhere-opensource-src-5.10.0.tar.xz"
+  sha256 "936d4cf5d577298f4f9fdb220e85b008ae321554a5fcd38072dc327a7296230e"
+  head "https://code.qt.io/qt/qt5.git", :branch => "5.10", :shallow => false
+
+  bottle do
+    sha256 "332ab2f3eb7c13510f460c13d28a562db03297149a3615feb9e3d467fafde56c" => :high_sierra
+    sha256 "c93cf6ead1774cfa7a369c92c7d6a69154bc0dd5b48a0e7ddf3a78202c4a3dc5" => :sierra
+    sha256 "44425e23d8b9c2b8b2f50d850ca94dcd411cd89e20e057c8d6505c9056d06328" => :el_capitan
+  end
+
+  keg_only "Qt 5 has CMake issues when linked"
+
+  option "with-docs", "Build documentation"
+  option "with-examples", "Build examples"
+  
+  deprecated_option "with-mysql" => "with-mysql-client"
+
+  # OS X 10.7 Lion is still supported in Qt 5.5, but is no longer a reference
+  # configuration and thus untested in practice. Builds on OS X 10.7 have been
+  # reported to fail: <https://github.com/Homebrew/homebrew/issues/45284>.
+  depends_on :macos => :mountain_lion
+
+  depends_on "pkg-config" => :build
+  depends_on :xcode => :build
+  depends_on "mysql-client" => :optional
+  depends_on "postgresql" => :optional
+
+  # Restore `.pc` files for framework-based build of Qt 5 on OS X. This
+  # partially reverts <https://codereview.qt-project.org/#/c/140954/> merged
+  # between the 5.5.1 and 5.6.0 releases. (Remove this as soon as feasible!)
+  #
+  # Core formulae known to fail without this patch (as of 2016-10-15):
+  #   * gnuplot  (with `--with-qt` option)
+  #   * mkvtoolnix (with `--with-qt` option, silent build failure)
+  #   * poppler    (with `--with-qt` option)
+  patch do
+    url "https://raw.githubusercontent.com/Homebrew/formula-patches/e8fe6567/qt5/restore-pc-files.patch"
+    sha256 "48ff18be2f4050de7288bddbae7f47e949512ac4bcd126c2f504be2ac701158b"
+  end
+
+  # Remove for > 5.10.0
+  # Fix "error: 'loadFileURL:allowingReadAccessToURL:' is only available on
+  # macOS 10.11 or newer [-Werror,-Wunguarded-availability]"
+  # Reported 8 Dec 2017 https://bugreports.qt.io/browse/QTBUG-65075
+  # Equivalent to upstream fix from 8 Dec 2017 https://codereview.qt-project.org/#/c/213993/
+  if MacOS::Xcode.version >= "9.0"
+    patch do
+      url "https://raw.githubusercontent.com/Homebrew/formula-patches/9c97726e2b153099049326ade23fe24b52b778fe/qt/QTBUG-65075.diff"
+      sha256 "a51595868c6173ab53463107e0ee3355576002c32ab80897587c3607589cfd22"
+    end
+  end
+
+  def install
+    args = %W[
+      -verbose
+      -prefix #{prefix}
+      -release
+      -opensource -confirm-license
+      -system-zlib
+      -qt-libpng
+      -qt-libjpeg
+      -qt-freetype
+      -qt-pcre
+      -nomake tests
+      -no-rpath
+      -pkg-config
+      -dbus-runtime
+    ]
+
+    args << "-nomake" << "examples" if build.without? "examples"
+
+    if build.with? "mysql-client"
+      args << "-plugin-sql-mysql"
+      (buildpath/"brew_shim/mysql_config").write <<~EOS
+        #!/bin/sh
+        if [ x"$1" = x"--libs" ]; then
+          mysql_config --libs | sed "s/-lssl -lcrypto//"
+        else
+          exec mysql_config "$@"
+        fi
+      EOS
+      chmod 0755, "brew_shim/mysql_config"
+      args << "-mysql_config" << buildpath/"brew_shim/mysql_config"
+    end
+
+    args << "-plugin-sql-psql" if build.with? "postgresql"
+
+    system "./configure", *args
+    system "make"
+    ENV.deparallelize
+    system "make", "install"
+
+    if build.with? "docs"
+      system "make", "docs"
+      system "make", "install_docs"
+    end
+
+    # Some config scripts will only find Qt in a "Frameworks" folder
+    frameworks.install_symlink Dir["#{lib}/*.framework"]
+
+    # The pkg-config files installed suggest that headers can be found in the
+    # `include` directory. Make this so by creating symlinks from `include` to
+    # the Frameworks' Headers folders.
+    Pathname.glob("#{lib}/*.framework/Headers") do |path|
+      include.install_symlink path => path.parent.basename(".framework")
+    end
+
+    # Move `*.app` bundles into `libexec` to expose them to `brew linkapps` and
+    # because we don't like having them in `bin`.
+    # (Note: This move breaks invocation of Assistant via the Help menu
+    # of both Designer and Linguist as that relies on Assistant being in `bin`.)
+    libexec.mkpath
+    Pathname.glob("#{bin}/*.app") { |app| mv app, libexec }
+  end
+
+  def caveats; <<~EOS
+    We agreed to the Qt opensource license for you.
+    If this is unacceptable you should uninstall.
+    EOS
+  end
+
+  test do
+    (testpath/"hello.pro").write <<~EOS
+      QT       += core
+      QT       -= gui
+      TARGET = hello
+      CONFIG   += console
+      CONFIG   -= app_bundle
+      TEMPLATE = app
+      SOURCES += main.cpp
+    EOS
+
+    (testpath/"main.cpp").write <<~EOS
+      #include <QCoreApplication>
+      #include <QDebug>
+
+      int main(int argc, char *argv[])
+      {
+        QCoreApplication a(argc, argv);
+        qDebug() << "Hello World!";
+        return 0;
+      }
+    EOS
+
+    system bin/"qmake", testpath/"hello.pro"
+    system "make"
+    assert_predicate testpath/"hello", :exist?
+    assert_predicate testpath/"main.o", :exist?
+    system "./hello"
+  end
+end