diff --git a/build/moz.configure/nspr.configure b/build/moz.configure/nspr.configure
index 43afa04df0d0..315691ce0214 100644
--- a/build/moz.configure/nspr.configure
+++ b/build/moz.configure/nspr.configure
@@ -6,17 +6,17 @@
 
 # Top-level configure defaults to building NSPR from source. Standalone JS
 # doesn't.
-js_option('--enable-nspr-build', when=building_js,
+js_option('--enable-nspr-build', when=js_standalone,
           help='{Build|Do not build} NSPR from source tree')
 
-@depends('--enable-nspr-build', when=building_js)
+@depends('--enable-nspr-build', when=js_standalone)
 def enable_nspr_build(enable):
     if enable:
         return enable
 
 js_option('--with-system-nspr', help='Use system NSPR')
 
-@depends(enable_nspr_build, '--with-system-nspr', 'JS_STANDALONE')
+@depends(enable_nspr_build, '--with-system-nspr', js_standalone)
 def build_nspr(nspr_build, system_nspr, js_standalone):
     if nspr_build is not None and nspr_build.origin != 'default':
         if nspr_build and system_nspr:
@@ -28,17 +28,17 @@ def build_nspr(nspr_build, system_nspr, js_standalone):
 set_config('MOZ_BUILD_NSPR', True, when=build_nspr)
 set_config('MOZ_SYSTEM_NSPR', True, when='--with-system-nspr')
 
-@depends(build_nspr, '--with-system-nspr', building_js)
-def js_without_nspr(build_nspr, system_nspr, building_js):
-    if building_js:
+@depends(build_nspr, '--with-system-nspr', js_standalone)
+def js_without_nspr(build_nspr, system_nspr, js_standalone):
+    if js_standalone:
         return not build_nspr and not system_nspr
 
 set_config('JS_WITHOUT_NSPR', True, when=js_without_nspr)
 set_define('JS_WITHOUT_NSPR', True, when=js_without_nspr)
 
-@depends(building_js)
-def nspr_minver(building_js):
-    if building_js:
+@depends(js_standalone)
+def nspr_minver(js_standalone):
+    if js_standalone:
         return 'nspr >= 4.10'
     return 'nspr >= 4.26'
 
diff --git a/js/moz.configure b/js/moz.configure
index 928f5321117b..1c92a90cfa4c 100644
--- a/js/moz.configure
+++ b/js/moz.configure
@@ -8,15 +8,9 @@
 # =========================================================
 
 @depends(build_project)
-def building_js(build_project):
-    return build_project == 'js'
-
-# Exception to the rule above: JS_STANDALONE is a special option that doesn't
-# want the js_option treatment. When we're done merging js/src/configure and
-# top-level configure, it can go away, although the JS_STANDALONE config
-# will still need to be set depending on building_js above.
-option(env='JS_STANDALONE', default=building_js,
-       help='Reserved for internal use')
+def js_standalone(build_project):
+    if build_project == 'js':
+        return True
 
 # Branding
 # ==============================================================
@@ -24,7 +18,7 @@ js_option('--with-app-name', env='MOZ_APP_NAME', nargs=1,
           help='Used for e.g. the binary program file name. If not set, '
           'defaults to a lowercase form of MOZ_APP_BASENAME.')
 
-@depends('--with-app-name', 'JS_STANDALONE', moz_app_basename)
+@depends('--with-app-name', js_standalone, moz_app_basename)
 def moz_app_name(value, js_standalone, moz_app_basename):
     if value:
         return value[0]
@@ -56,17 +50,13 @@ include('../build/moz.configure/rust.configure',
 include('../build/moz.configure/bindgen.configure',
         when='--enable-compile-environment')
 
-@depends('JS_STANDALONE')
-def js_standalone(value):
-    if value:
-        return True
 set_config('JS_STANDALONE', js_standalone)
 set_define('JS_STANDALONE', js_standalone)
 add_old_configure_assignment('JS_STANDALONE', js_standalone)
-js_option('--disable-js-shell', default=building_js,
+js_option('--enable-js-shell', default=js_standalone,
           help='{Build|Do not build} the JS shell')
 
-@depends('--disable-js-shell')
+@depends('--enable-js-shell')
 def js_disable_shell(value):
     if not value:
         return True
@@ -420,9 +410,9 @@ set_define('JS_MORE_DETERMINISTIC', more_deterministic)
 
 # CTypes
 # =======================================================
-@depends(building_js)
-def ctypes_default(building_js):
-    return not building_js
+@depends(js_standalone)
+def ctypes_default(js_standalone):
+    return not js_standalone
 
 js_option('--enable-ctypes',
           default=ctypes_default,
@@ -771,9 +761,9 @@ set_define('MOZ_SYSTEM_ICU', True, when=system_icu)
 
 js_option('--without-intl-api', help='Disable ECMAScript Internationalization API')
 
-@depends('--with-intl-api', building_js)
-def check_intl_api(enabled, building_js):
-    if not enabled and not building_js:
+@depends('--with-intl-api', js_standalone)
+def check_intl_api(enabled, js_standalone):
+    if not enabled and not js_standalone:
         die('--without-intl-api is not supported')
 
 set_config('JS_HAS_INTL_API', True, when='--with-intl-api')
diff --git a/tools/update-programs/moz.configure b/tools/update-programs/moz.configure
index 306719e33658..0b28a7aee971 100644
--- a/tools/update-programs/moz.configure
+++ b/tools/update-programs/moz.configure
@@ -4,14 +4,10 @@
 
 # Spoof a stub of `js/moz.configure` for the included scripts.
 @dependable
-def building_js():
+def js_standalone():
     return False
 
 
-option(env='JS_STANDALONE', default=building_js,
-       help='Reserved for internal use')
-
-
 @depends(target)
 def fold_libs(target):
     return target.os in ('WINNT', 'OSX', 'Android')