--- a/b2g/confvars.sh
+++ b/b2g/confvars.sh
@@ -18,17 +18,16 @@ MOZ_OFFICIAL_BRANDING_DIRECTORY=b2g/bran
 # MOZ_APP_DISPLAYNAME is set by branding/configure.sh
 
 MOZ_SAFE_BROWSING=1
 
 MOZ_NO_SMART_CARDS=1
 MOZ_APP_STATIC_INI=1
 MOZ_NO_EV_CERTS=1
 
-MOZ_WEBSPEECH=1
 if test -n "$NIGHTLY_BUILD"; then
 MOZ_WEBSPEECH_MODELS=1
 fi
 MOZ_WEBSPEECH_TEST_BACKEND=1
 
 if test "$OS_TARGET" = "Android"; then
 MOZ_CAPTURE=1
 MOZ_RAW=1

--- a/build/moz.configure/old.configure
+++ b/build/moz.configure/old.configure
@@ -242,17 +242,16 @@ def old_configure_options(*options):
     '--enable-tree-freetype',
     '--enable-ui-locale',
     '--enable-universalchardet',
     '--enable-updater',
     '--enable-url-classifier',
     '--enable-valgrind',
     '--enable-verify-mar',
     '--enable-webrtc',
-    '--enable-webspeech',
     '--enable-webspeechtestbackend',
     '--enable-xul',
     '--enable-zipwriter',
     '--no-create',
     '--prefix',
     '--with-android-cxx-stl',
     '--with-android-distribution-directory',
     '--with-android-max-sdk',

--- a/old-configure.in
+++ b/old-configure.in
@@ -2329,17 +2329,16 @@ MOZ_PEERCONNECTION=
 MOZ_SRTP=
 MOZ_WEBRTC_SIGNALING=
 MOZ_WEBRTC_ASSERT_ALWAYS=1
 MOZ_WEBRTC_HARDWARE_AEC_NS=
 MOZ_SCTP=
 MOZ_ANDROID_OMX=
 MOZ_OMX_PLUGIN=
 MOZ_VPX_ERROR_CONCEALMENT=
-MOZ_WEBSPEECH=1
 MOZ_WEBSPEECH_MODELS=
 MOZ_WEBSPEECH_TEST_BACKEND=1
 VPX_USE_YASM=
 VPX_ASFLAGS=
 VPX_AS_CONVERSION=
 VPX_X86_ASM=
 VPX_ARM_ASM=
 LIBJPEG_TURBO_AS=
@@ -3002,30 +3001,16 @@ if test "$OS_TARGET" = "Android" -o "$CP
     AC_SUBST(MOZ_SAMPLE_TYPE_S16)
 else
     MOZ_SAMPLE_TYPE_FLOAT32=1
     AC_DEFINE(MOZ_SAMPLE_TYPE_FLOAT32)
     AC_SUBST(MOZ_SAMPLE_TYPE_FLOAT32)
 fi
 
 dnl ========================================================
-dnl = Disable Speech API code
-dnl ========================================================
-MOZ_ARG_DISABLE_BOOL(webspeech,
-[  --disable-webspeech        Disable support for HTML Speech API],
-    MOZ_WEBSPEECH=,
-    MOZ_WEBSPEECH=1)
-
-if test -n "$MOZ_WEBSPEECH"; then
-    AC_DEFINE(MOZ_WEBSPEECH)
-fi
-
-AC_SUBST(MOZ_WEBSPEECH)
-
-dnl ========================================================
 dnl = Disable Speech API test backend
 dnl ========================================================
 MOZ_ARG_DISABLE_BOOL(webspeechtestbackend,
 [  --disable-webspeechtestbackend        Disable support for HTML Speech API Test Backend],
     MOZ_WEBSPEECH_TEST_BACKEND=,
     MOZ_WEBSPEECH_TEST_BACKEND=1)
 
 if test -z "$MOZ_WEBSPEECH"; then

--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -536,21 +536,34 @@ def no_speechd_on_non_gtk(toolkit):
 imply_option('--enable-synth-speechd', no_speechd_on_non_gtk,
              reason='--enable-default-toolkit')
 
 option('--disable-synth-speechd', help='Disable speech-dispatcher support')
 
 set_config('MOZ_SYNTH_SPEECHD',
            depends_if('--disable-synth-speechd')(lambda _: True))
 
+# Speech API
+# ==============================================================
+option('--disable-webspeech', help='Disable support for HTML Speech API')
+
+@depends('--disable-webspeech')
+def webspeech(value):
+    if value:
+        return True
+
+set_config('MOZ_WEBSPEECH', webspeech)
+set_define('MOZ_WEBSPEECH', webspeech)
+add_old_configure_assignment('MOZ_WEBSPEECH', webspeech)
+
 # Speech API pocketsphinx backend
 # ==============================================================
-@depends(build_project, milestone)
-def webspeech_pocketsphinx(build_project, milestone):
-    if milestone.is_nightly and build_project == 'b2g':
+@depends(build_project, milestone, webspeech)
+def webspeech_pocketsphinx(build_project, milestone, webspeech):
+    if webspeech and milestone.is_nightly and build_project == 'b2g':
         return True
 
 set_config('MOZ_WEBSPEECH_POCKETSPHINX', webspeech_pocketsphinx)
 set_define('MOZ_WEBSPEECH_POCKETSPHINX', webspeech_pocketsphinx)
 
 # WebSMS
 # ==============================================================
 @depends(build_project, '--help')