--- a/build/autoconf/android.m4
+++ b/build/autoconf/android.m4
@@ -3,22 +3,22 @@ dnl License, v. 2.0. If a copy of the MP
 dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 AC_DEFUN([MOZ_ANDROID_NDK],
 [
 
 case "$target" in
 *-android*|*-linuxandroid*)
     dnl $android_platform will be set for us by Python configure.
-    directory_include_args="-isystem $android_platform/usr/include"
+    directory_include_args="-isystem $android_system -isystem $android_sysroot/usr/include"
 
     # clang will do any number of interesting things with host tools unless we tell
     # it to use the NDK tools.
     extra_opts="-gcc-toolchain $(dirname $(dirname $TOOLCHAIN_PREFIX))"
-    CPPFLAGS="$extra_opts $CPPFLAGS"
+    CPPFLAGS="$extra_opts -D__ANDROID_API__=$android_version $CPPFLAGS"
     ASFLAGS="$extra_opts $ASFLAGS"
     LDFLAGS="$extra_opts $LDFLAGS"
 
     CPPFLAGS="$directory_include_args $CPPFLAGS"
     CFLAGS="-fno-short-enums -fno-exceptions $CFLAGS"
     CXXFLAGS="-fno-short-enums -fno-exceptions $CXXFLAGS $stlport_cppflags"
     ASFLAGS="$directory_include_args -DANDROID $ASFLAGS"
 

--- a/build/moz.configure/android-ndk.configure
+++ b/build/moz.configure/android-ndk.configure
@@ -145,16 +145,66 @@ def android_platform(target, android_ver
             "configuration, it should be in %s" % platform_dir)
 
     return platform_dir
 
 
 add_old_configure_assignment('android_platform', android_platform)
 
 
+@depends(android_platform, ndk, target, '--help')
+@checking('for android sysroot directory')
+@imports(_from='os.path', _import='isdir')
+def android_sysroot(android_platform, ndk, target, _):
+    if target.os != 'Android':
+        return
+
+    # NDK r15 has both unified and non-unified headers, but we only support
+    # non-unified for that NDK, so look for that first.
+    search_dirs = [
+        # (<if this directory exists>, <return this directory>)
+        (os.path.join(android_platform, 'usr', 'include'), android_platform),
+        (os.path.join(ndk, 'sysroot'), os.path.join(ndk, 'sysroot')),
+    ]
+
+    for test_dir, sysroot_dir in search_dirs:
+        if isdir(test_dir):
+            return sysroot_dir
+
+    die("Android sysroot directory not found in %s." %
+        str([sysroot_dir for test_dir, sysroot_dir in search_dirs]))
+
+
+add_old_configure_assignment('android_sysroot', android_sysroot)
+
+
+@depends(android_platform, ndk, target, '--help')
+@checking('for android system directory')
+@imports(_from='os.path', _import='isdir')
+def android_system(android_platform, ndk, target, _):
+    if target.os != 'Android':
+        return
+
+    # NDK r15 has both unified and non-unified headers, but we only support
+    # non-unified for that NDK, so look for that first.
+    search_dirs = [
+        os.path.join(android_platform, 'usr', 'include'),
+        os.path.join(ndk, 'sysroot', 'usr', 'include', target.toolchain),
+    ]
+
+    for system_dir in search_dirs:
+        if isdir(system_dir):
+            return system_dir
+
+    die("Android system directory not found in %s." % str(search_dirs))
+
+
+add_old_configure_assignment('android_system', android_system)
+
+
 @depends(target, host, ndk, '--with-android-toolchain', '--help')
 @checking('for the Android toolchain directory', lambda x: x or 'not found')
 @imports(_from='os.path', _import='isdir')
 @imports(_from='mozbuild.shellutil', _import='quote')
 def android_toolchain(target, host, ndk, toolchain, _):
     if not ndk:
         return
     if toolchain:
@@ -236,24 +286,29 @@ def stlport_cppflags(value, ndk, _):
         '-I%s' % cxx_include,
         '-I%s' % os.path.join(ndk, 'sources', 'android', 'support', 'include'),
         '-I%s' % cxxabi_include]
 
 
 add_old_configure_assignment('stlport_cppflags', stlport_cppflags)
 
 
-@depends(android_platform, android_toolchain, stlport_cppflags)
-def extra_toolchain_flags(platform_dir, toolchain_dir, stlport_cppflags):
-    if not platform_dir:
+@depends(android_system, android_sysroot, android_toolchain, android_version,
+         stlport_cppflags)
+def extra_toolchain_flags(android_system, android_sysroot, toolchain_dir,
+                          android_version, stlport_cppflags):
+    if not android_sysroot:
         return []
     flags = ['-isystem',
-             os.path.join(platform_dir, 'usr', 'include'),
+             android_system,
+             '-isystem',
+             os.path.join(android_sysroot, 'usr', 'include'),
              '-gcc-toolchain',
-             toolchain_dir]
+             toolchain_dir,
+             '-D__ANDROID_API__=%d' % android_version]
     flags.extend(stlport_cppflags if stlport_cppflags else [])
     return flags
 
 
 @depends(android_toolchain_prefix_base, android_toolchain)
 def android_toolchain_prefix(prefix_base, toolchain):
     if toolchain:
         return '%s/bin/%s-' % (toolchain, prefix_base)