--- a/build/moz.configure/windows.configure
+++ b/build/moz.configure/windows.configure
@@ -146,16 +146,123 @@ add_old_configure_assignment(
     'WINDOWSSDKDIR',
     delayed_getattr(valid_windows_sdk_dir, 'path'))
 add_old_configure_assignment(
     'MOZ_WINSDK_MAXVER',
     depends(valid_windows_sdk_dir)(
         lambda x: '0x%04X0000' % x.version if x else None))
 
 
+@imports(_from='mozbuild.shellutil', _import='quote')
+def valid_ucrt_sdk_dir_result(value):
+    if value:
+        return '%s in %s' % (value.version, quote(value.path))
+
+@depends_win(windows_sdk_dir, 'WINDOWSSDKDIR')
+@checking('for Universal CRT SDK', valid_ucrt_sdk_dir_result)
+@imports(_from='__builtin__', _import='sorted')
+def valid_ucrt_sdk_dir(windows_sdk_dir, windows_sdk_dir_env):
+    if windows_sdk_dir_env:
+        windows_sdk_dir_env = windows_sdk_dir_env[0]
+    sdks = {}
+    for d in windows_sdk_dir:
+        ucrt_dir = get_include_dir(d, 'ucrt')
+        if ucrt_dir:
+            version = os.path.basename(os.path.dirname(ucrt_dir))
+            # We're supposed to always find a version in the directory, because
+            # the 8.1 SDK, which doesn't have a version in the directory, doesn't
+            # contain the Universal CRT SDK. When the main SDK is 8.1, there
+            # is, however, supposed to be a reduced install of the SDK 10
+            # with the UCRT.
+            if version != 'include':
+                sdks[d] = Version(version)
+                continue
+        if d == windows_sdk_dir_env:
+            raise FatalCheckError(
+                'The SDK in WINDOWSSDKDIR (%s) does not contain the Universal '
+                'CRT.' % windows_sdk_dir_env)
+
+    valid_sdks = sorted(sdks, key=lambda x: sdks[x], reverse=True)
+    if not valid_sdks:
+        raise FatalCheckError('Cannot find the Universal CRT SDK. '
+                              'Please install it.')
+
+    return namespace(
+        path=valid_sdks[0],
+        version=sdks[valid_sdks[0]],
+    )
+
+
+@depends_win(c_compiler)
+@imports('os')
+def vc_path(c_compiler):
+    if c_compiler.type != 'msvc':
+        return
+    # Normally, we'd start from c_compiler.compiler, but for now, it's not the
+    # ideal full path to the compiler. At least, we're guaranteed find_program
+    # will get us the one we found in toolchain.configure.
+    cl = find_program(c_compiler.compiler)
+    result = os.path.dirname(cl)
+    while True:
+        next, p = os.path.split(result)
+        if next == result:
+            die('Cannot determine the Visual C++ directory the compiler (%s) '
+                'is in' % cl)
+        result = next
+        if p.lower() == 'bin':
+            break
+    return result
+
+
+@depends_win(vc_path)
+@checking('for the Debug Interface Access SDK', lambda x: x or 'not found')
+def dia_sdk_dir(vc_path):
+    if vc_path:
+        path = os.path.join(os.path.dirname(vc_path), 'DIA SDK')
+        if os.path.isdir(path):
+            return path
+
+
+@depends_win(vc_path, valid_windows_sdk_dir, valid_ucrt_sdk_dir, dia_sdk_dir)
+@imports('os')
+def include_path(vc_path, windows_sdk_dir, ucrt_sdk_dir, dia_sdk_dir):
+    if not vc_path:
+        return
+    atlmfc_dir = os.path.join(vc_path, 'atlmfc', 'include')
+    if not os.path.isdir(atlmfc_dir):
+        die('Cannot find the ATL/MFC headers in the Visual C++ directory (%s). '
+            'Please install them.' % vc_path)
+
+    winrt_dir = get_include_dir(windows_sdk_dir.path, 'winrt')
+    if not os.path.isdir(winrt_dir):
+        die('Cannot find the WinRT headers in the Windows SDK directory (%s). '
+            'Please install them.' % windows_sdk_dir.path)
+
+    includes = []
+    include_env = os.environ.get('INCLUDE')
+    if include_env:
+        includes.append(include_env)
+    includes.extend((
+        os.path.join(vc_path, 'include'),
+        atlmfc_dir,
+        get_include_dir(windows_sdk_dir.path, 'shared'),
+        get_include_dir(windows_sdk_dir.path, 'um'),
+        winrt_dir,
+        get_include_dir(ucrt_sdk_dir.path, 'ucrt'),
+    ))
+    if dia_sdk_dir:
+        includes.append(os.path.join(dia_sdk_dir, 'include'))
+    # Set in the environment for old-configure
+    includes = os.pathsep.join(includes)
+    os.environ['INCLUDE'] = includes
+    return includes
+
+set_config('INCLUDE', include_path)
+
+
 option(env='MT', nargs=1, help='Path to the Microsoft Manifest Tool')
 
 @depends_win(valid_windows_sdk_dir)
 @imports(_from='os', _import='environ')
 @imports('platform')
 def sdk_bin_path(valid_windows_sdk_dir):
     if not valid_windows_sdk_dir:
         return

--- a/config/config.mk
+++ b/config/config.mk
@@ -353,16 +353,22 @@ SDK_LIB_DIR = $(DIST)/sdk/lib
 SDK_BIN_DIR = $(DIST)/sdk/bin
 
 DEPENDENCIES	= .md
 
 ifdef MACOSX_DEPLOYMENT_TARGET
 export MACOSX_DEPLOYMENT_TARGET
 endif # MACOSX_DEPLOYMENT_TARGET
 
+# Export to propagate to cl and submake for third-party code.
+# Eventually, we'll want to just use -I.
+ifdef INCLUDE
+export INCLUDE
+endif
+
 ifdef MOZ_USING_CCACHE
 ifdef CLANG_CXX
 export CCACHE_CPP2=1
 endif
 endif
 
 # Set link flags according to whether we want a console.
 ifeq ($(OS_ARCH),WINNT)