--- a/b2g/confvars.sh
+++ b/b2g/confvars.sh
@@ -18,20 +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
 
-if test -n "$NIGHTLY_BUILD"; then
-MOZ_WEBSPEECH_MODELS=1
-fi
-
 if test "$OS_TARGET" = "Android"; then
 MOZ_CAPTURE=1
 MOZ_RAW=1
 MOZ_AUDIO_CHANNEL_MANAGER=1
 fi
 
 # use custom widget for html:select
 MOZ_USE_NATIVE_POPUP_WINDOWS=1

--- 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_MODELS=
 VPX_USE_YASM=
 VPX_ASFLAGS=
 VPX_AS_CONVERSION=
 VPX_X86_ASM=
 VPX_ARM_ASM=
 LIBJPEG_TURBO_AS=
 LIBJPEG_TURBO_ASFLAGS=
 MOZ_PERMISSIONS=1
@@ -3000,29 +2999,16 @@ 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 models
-dnl ========================================================
-if test -z "$MOZ_WEBSPEECH"; then
-MOZ_WEBSPEECH_MODELS=
-fi
-
-if test -n "$MOZ_WEBSPEECH_MODELS"; then
-    AC_DEFINE(MOZ_WEBSPEECH_MODELS)
-fi
-
-AC_SUBST(MOZ_WEBSPEECH_MODELS)
-
-dnl ========================================================
 dnl = Enable Raw Codecs
 dnl ========================================================
 MOZ_ARG_ENABLE_BOOL(raw,
 [  --enable-raw           Enable support for RAW media],
     MOZ_RAW=1,
     MOZ_RAW=)
 
 if test -n "$MOZ_RAW"; then

--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -559,16 +559,26 @@ add_old_configure_assignment('MOZ_WEBSPE
 @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)
 
+# Speech API models
+# ==============================================================
+@depends(build_project, milestone, webspeech)
+def webspeech_models(build_project, milestone, webspeech):
+    if webspeech and milestone.is_nightly and build_project == 'b2g':
+        return True
+
+set_config('MOZ_WEBSPEECH_MODELS', webspeech_models)
+set_define('MOZ_WEBSPEECH_MODELS', webspeech_models)
+
 # Speech API test backend
 # ==============================================================
 option('--enable-webspeechtestbackend', default=webspeech,
        help='Enable support for HTML Speech API Test Backend')
 
 @depends_if('--enable-webspeechtestbackend')
 def webspeech_test_backend(value):
     return True