diff --git a/accessible/public/moz.build b/accessible/public/moz.build
index be9cc2aea0dcff..9c6446b8f37595 100644
--- a/accessible/public/moz.build
+++ b/accessible/public/moz.build
@@ -35,7 +35,7 @@ XPIDL_SOURCES += [
     'nsIXBLAccessible.idl',
 ]
 
-MODULE = 'accessibility'
+XPIDL_MODULE = 'accessibility'
 
 EXPORTS += [
     'nsIAccessibilityService.h',
diff --git a/browser/components/feeds/public/moz.build b/browser/components/feeds/public/moz.build
index aa73befb979765..3f1b6d29a93679 100644
--- a/browser/components/feeds/public/moz.build
+++ b/browser/components/feeds/public/moz.build
@@ -10,5 +10,5 @@ XPIDL_SOURCES += [
     'nsIWebContentConverterRegistrar.idl',
 ]
 
-MODULE = 'browser-feeds'
+XPIDL_MODULE = 'browser-feeds'
 
diff --git a/browser/components/migration/public/moz.build b/browser/components/migration/public/moz.build
index ec07bba1e52668..b496622bc3cbf4 100644
--- a/browser/components/migration/public/moz.build
+++ b/browser/components/migration/public/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'nsIBrowserProfileMigrator.idl',
 ]
 
-MODULE = 'migration'
+XPIDL_MODULE = 'migration'
 
diff --git a/browser/components/sessionstore/moz.build b/browser/components/sessionstore/moz.build
index fefd9cc3975acd..59bb71ca6a4e71 100644
--- a/browser/components/sessionstore/moz.build
+++ b/browser/components/sessionstore/moz.build
@@ -11,7 +11,7 @@ XPIDL_SOURCES += [
     'nsISessionStore.idl',
 ]
 
-MODULE = 'sessionstore'
+XPIDL_MODULE = 'sessionstore'
 
 XPCSHELL_TESTS_MANIFESTS += [
     'test/unit/xpcshell.ini',
diff --git a/browser/components/shell/public/moz.build b/browser/components/shell/public/moz.build
index 080193ce3aad41..53f78cb6d1e07e 100644
--- a/browser/components/shell/public/moz.build
+++ b/browser/components/shell/public/moz.build
@@ -17,5 +17,5 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
         'nsIMacShellService.idl',
     ]
 
-MODULE = 'shellservice'
+XPIDL_MODULE = 'shellservice'
 
diff --git a/browser/fuel/public/moz.build b/browser/fuel/public/moz.build
index 4bf19f7531b962..fe0f7e3ac31cbc 100644
--- a/browser/fuel/public/moz.build
+++ b/browser/fuel/public/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'fuelIApplication.idl',
 ]
 
-MODULE = 'fuel'
+XPIDL_MODULE = 'fuel'
 
diff --git a/browser/metro/components/moz.build b/browser/metro/components/moz.build
index 486d3597720e4f..026feb8d6ebfda 100644
--- a/browser/metro/components/moz.build
+++ b/browser/metro/components/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'SessionStore.idl',
 ]
 
-MODULE = 'components'
+XPIDL_MODULE = 'components'
 
 # metro/components.manifest
 EXTRA_COMPONENTS += [
diff --git a/caps/idl/moz.build b/caps/idl/moz.build
index bf392583227cd9..d9f7b944621b76 100644
--- a/caps/idl/moz.build
+++ b/caps/idl/moz.build
@@ -11,5 +11,5 @@ XPIDL_SOURCES += [
     'nsISecurityCheckedComponent.idl',
 ]
 
-MODULE = 'caps'
+XPIDL_MODULE = 'caps'
 
diff --git a/chrome/public/moz.build b/chrome/public/moz.build
index 1074d1925e78f7..ab333b726680c6 100644
--- a/chrome/public/moz.build
+++ b/chrome/public/moz.build
@@ -9,5 +9,5 @@ XPIDL_SOURCES += [
     'nsIToolkitChromeRegistry.idl',
 ]
 
-MODULE = 'chrome'
+XPIDL_MODULE = 'chrome'
 
diff --git a/content/xul/content/public/moz.build b/content/xul/content/public/moz.build
index 22b3f42a406814..f45c9902222e15 100644
--- a/content/xul/content/public/moz.build
+++ b/content/xul/content/public/moz.build
@@ -9,5 +9,5 @@ if CONFIG['MOZ_XUL']:
         'nsIXULContextMenuBuilder.idl',
     ]
 
-MODULE = 'xul'
+XPIDL_MODULE = 'xul'
 
diff --git a/content/xul/document/public/moz.build b/content/xul/document/public/moz.build
index 372dad688bb708..7c457d06f14b24 100644
--- a/content/xul/document/public/moz.build
+++ b/content/xul/document/public/moz.build
@@ -17,5 +17,5 @@ if CONFIG['MOZ_XUL']:
         'nsIXULDocument.h',
     ]
 
-MODULE = 'xuldoc'
+XPIDL_MODULE = 'xuldoc'
 
diff --git a/content/xul/templates/public/moz.build b/content/xul/templates/public/moz.build
index 5cbd717d426823..f20810747b8d28 100644
--- a/content/xul/templates/public/moz.build
+++ b/content/xul/templates/public/moz.build
@@ -13,5 +13,5 @@ XPIDL_SOURCES += [
     'nsIXULTemplateRuleFilter.idl',
 ]
 
-MODULE = 'xultmpl'
+XPIDL_MODULE = 'xultmpl'
 
diff --git a/docshell/base/moz.build b/docshell/base/moz.build
index ab028cae799786..1046275119df4e 100644
--- a/docshell/base/moz.build
+++ b/docshell/base/moz.build
@@ -33,7 +33,7 @@ XPIDL_SOURCES += [
     'nsIWebPageDescriptor.idl',
 ]
 
-MODULE = 'docshell'
+XPIDL_MODULE = 'docshell'
 
 EXPORTS += [
     'nsDocShellLoadTypes.h',
diff --git a/docshell/shistory/public/moz.build b/docshell/shistory/public/moz.build
index 7e520850310ec4..4bfb0ea10edd5f 100644
--- a/docshell/shistory/public/moz.build
+++ b/docshell/shistory/public/moz.build
@@ -14,5 +14,5 @@ XPIDL_SOURCES += [
     'nsISHTransaction.idl',
 ]
 
-MODULE = 'shistory'
+XPIDL_MODULE = 'shistory'
 
diff --git a/dom/base/moz.build b/dom/base/moz.build
index adcbede9530626..6b12a5829a90d8 100644
--- a/dom/base/moz.build
+++ b/dom/base/moz.build
@@ -14,7 +14,7 @@ XPIDL_SOURCES += [
     'nsISiteSpecificUserAgent.idl',
 ]
 
-MODULE = 'dom'
+XPIDL_MODULE = 'dom'
 
 EXPORTS += [
     'Crypto.h',
diff --git a/dom/media/bridge/moz.build b/dom/media/bridge/moz.build
index 91dc07b22f1d6a..ab19b8849f1e5f 100644
--- a/dom/media/bridge/moz.build
+++ b/dom/media/bridge/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'IPeerConnection.idl',
 ]
 
-MODULE = 'peerconnection'
+XPIDL_MODULE = 'peerconnection'
 
 SOURCES += [
     'MediaModule.cpp',
diff --git a/dom/plugins/base/moz.build b/dom/plugins/base/moz.build
index 4cce64cb5e2ce1..ff9e19893d3aa3 100644
--- a/dom/plugins/base/moz.build
+++ b/dom/plugins/base/moz.build
@@ -18,7 +18,7 @@ XPIDL_SOURCES += [
     'nspluginroot.idl',
 ]
 
-MODULE = 'plugin'
+XPIDL_MODULE = 'plugin'
 
 EXPORTS += [
     'npapi.h',
diff --git a/editor/composer/public/moz.build b/editor/composer/public/moz.build
index 2775d53b43247b..8fd2fc7040bce3 100644
--- a/editor/composer/public/moz.build
+++ b/editor/composer/public/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'nsIEditingSession.idl',
 ]
 
-MODULE = 'composer'
+XPIDL_MODULE = 'composer'
 
diff --git a/editor/idl/moz.build b/editor/idl/moz.build
index 539e2e324e02e9..2d96292ab77dfa 100644
--- a/editor/idl/moz.build
+++ b/editor/idl/moz.build
@@ -25,5 +25,5 @@ XPIDL_SOURCES += [
     'nsPIEditorTransaction.idl',
 ]
 
-MODULE = 'editor'
+XPIDL_MODULE = 'editor'
 
diff --git a/editor/txmgr/idl/moz.build b/editor/txmgr/idl/moz.build
index e9cf1400b6de64..604fc6bc524d0c 100644
--- a/editor/txmgr/idl/moz.build
+++ b/editor/txmgr/idl/moz.build
@@ -11,5 +11,5 @@ XPIDL_SOURCES += [
     'nsITransactionManager.idl',
 ]
 
-MODULE = 'txmgr'
+XPIDL_MODULE = 'txmgr'
 
diff --git a/editor/txtsvc/public/moz.build b/editor/txtsvc/public/moz.build
index 23eeba229d76db..444dc53c2dd286 100644
--- a/editor/txtsvc/public/moz.build
+++ b/editor/txtsvc/public/moz.build
@@ -9,7 +9,7 @@ XPIDL_SOURCES += [
     'nsITextServicesFilter.idl',
 ]
 
-MODULE = 'txtsvc'
+XPIDL_MODULE = 'txtsvc'
 
 EXPORTS += [
     'nsISpellChecker.h',
diff --git a/embedding/base/moz.build b/embedding/base/moz.build
index d38888688ab27f..0536fbb8f1fc25 100644
--- a/embedding/base/moz.build
+++ b/embedding/base/moz.build
@@ -11,7 +11,7 @@ XPIDL_SOURCES += [
     'nsIWindowProvider.idl',
 ]
 
-MODULE = 'embed_base'
+XPIDL_MODULE = 'embed_base'
 
 EXPORTS += [
     'nsEmbedCID.h',
diff --git a/embedding/components/commandhandler/public/moz.build b/embedding/components/commandhandler/public/moz.build
index f880bd482d5c6e..68ebc5b550e0aa 100644
--- a/embedding/components/commandhandler/public/moz.build
+++ b/embedding/components/commandhandler/public/moz.build
@@ -13,5 +13,5 @@ XPIDL_SOURCES += [
     'nsPICommandUpdater.idl',
 ]
 
-MODULE = 'commandhandler'
+XPIDL_MODULE = 'commandhandler'
 
diff --git a/embedding/components/find/public/moz.build b/embedding/components/find/public/moz.build
index c89ad4c3d10077..82b76ae302ad22 100644
--- a/embedding/components/find/public/moz.build
+++ b/embedding/components/find/public/moz.build
@@ -9,5 +9,5 @@ XPIDL_SOURCES += [
     'nsIWebBrowserFind.idl',
 ]
 
-MODULE = 'find'
+XPIDL_MODULE = 'find'
 
diff --git a/embedding/components/webbrowserpersist/public/moz.build b/embedding/components/webbrowserpersist/public/moz.build
index 4b656d5836ecb8..77258df3e1fbe7 100644
--- a/embedding/components/webbrowserpersist/public/moz.build
+++ b/embedding/components/webbrowserpersist/public/moz.build
@@ -9,5 +9,5 @@ XPIDL_SOURCES += [
     'nsIWebBrowserPersist.idl',
 ]
 
-MODULE = 'webbrowserpersist'
+XPIDL_MODULE = 'webbrowserpersist'
 
diff --git a/embedding/components/windowwatcher/public/moz.build b/embedding/components/windowwatcher/public/moz.build
index 4a4e3def8eb4bf..7b24f3fa59b82f 100644
--- a/embedding/components/windowwatcher/public/moz.build
+++ b/embedding/components/windowwatcher/public/moz.build
@@ -14,7 +14,7 @@ XPIDL_SOURCES += [
     'nsPIWindowWatcher.idl',
 ]
 
-MODULE = 'windowwatcher'
+XPIDL_MODULE = 'windowwatcher'
 
 EXPORTS += [
     'nsPromptUtils.h',
diff --git a/extensions/cookie/moz.build b/extensions/cookie/moz.build
index 5d5e68e8278450..8ec3350386bc0e 100644
--- a/extensions/cookie/moz.build
+++ b/extensions/cookie/moz.build
@@ -11,7 +11,7 @@ XPIDL_SOURCES += [
     'nsICookiePromptService.idl',
 ]
 
-MODULE = 'cookie'
+XPIDL_MODULE = 'cookie'
 
 SOURCES += [
     'nsCookieModule.cpp',
diff --git a/extensions/pref/autoconfig/public/moz.build b/extensions/pref/autoconfig/public/moz.build
index 6dc02d5bfaed4e..b39b3d7998a2b0 100644
--- a/extensions/pref/autoconfig/public/moz.build
+++ b/extensions/pref/autoconfig/public/moz.build
@@ -9,5 +9,5 @@ XPIDL_SOURCES += [
     'nsIReadConfig.idl',
 ]
 
-MODULE = 'autoconfig'
+XPIDL_MODULE = 'autoconfig'
 
diff --git a/extensions/spellcheck/idl/moz.build b/extensions/spellcheck/idl/moz.build
index 53f2354e96f968..5c4a99db863ea0 100644
--- a/extensions/spellcheck/idl/moz.build
+++ b/extensions/spellcheck/idl/moz.build
@@ -11,5 +11,5 @@ XPIDL_SOURCES += [
     'mozISpellI18NUtil.idl',
 ]
 
-MODULE = 'spellchecker'
+XPIDL_MODULE = 'spellchecker'
 
diff --git a/gfx/src/moz.build b/gfx/src/moz.build
index 5eb56706202f89..a41f464325ef54 100644
--- a/gfx/src/moz.build
+++ b/gfx/src/moz.build
@@ -9,7 +9,7 @@ XPIDL_SOURCES += [
     'nsIScriptableRegion.idl',
 ]
 
-MODULE = 'gfx'
+XPIDL_MODULE = 'gfx'
 
 EXPORTS += [
     'gfxCore.h',
diff --git a/hal/moz.build b/hal/moz.build
index b583d15794961d..f38559907525f5 100644
--- a/hal/moz.build
+++ b/hal/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'gonk/nsIRecoveryService.idl',
 ]
 
-MODULE = 'hal'
+XPIDL_MODULE = 'hal'
 
 EXPORTS.mozilla += [
     'Hal.h',
diff --git a/image/decoders/icon/moz.build b/image/decoders/icon/moz.build
index 2d93231d91e001..9222a352e22d19 100644
--- a/image/decoders/icon/moz.build
+++ b/image/decoders/icon/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'nsIIconURI.idl',
 ]
 
-MODULE = 'imgicon'
+XPIDL_MODULE = 'imgicon'
 
 SOURCES += [
     'nsIconModule.cpp',
diff --git a/image/decoders/icon/qt/public/moz.build b/image/decoders/icon/qt/public/moz.build
index d66c0a13b60fbd..9e26f8b8b30e34 100644
--- a/image/decoders/icon/qt/public/moz.build
+++ b/image/decoders/icon/qt/public/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'nsGtkQtIconsConverter.idl',
 ]
 
-MODULE = 'gtkqticonsconverter'
+XPIDL_MODULE = 'gtkqticonsconverter'
 
diff --git a/image/public/moz.build b/image/public/moz.build
index bda4ba6ebdb505..b7de6c4e749625 100644
--- a/image/public/moz.build
+++ b/image/public/moz.build
@@ -17,7 +17,7 @@ XPIDL_SOURCES += [
     'imgITools.idl',
 ]
 
-MODULE = 'imglib2'
+XPIDL_MODULE = 'imglib2'
 
 EXPORTS += [
     'ImageLogging.h',
diff --git a/intl/locale/idl/moz.build b/intl/locale/idl/moz.build
index b5975fa8bbb44a..5b174b06e5f881 100644
--- a/intl/locale/idl/moz.build
+++ b/intl/locale/idl/moz.build
@@ -11,5 +11,5 @@ XPIDL_SOURCES += [
     'nsIScriptableDateFormat.idl',
 ]
 
-MODULE = 'locale'
+XPIDL_MODULE = 'locale'
 
diff --git a/intl/lwbrk/idl/moz.build b/intl/lwbrk/idl/moz.build
index d6b9b364bbf0ae..1f84f8c8ce20d3 100644
--- a/intl/lwbrk/idl/moz.build
+++ b/intl/lwbrk/idl/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'nsISemanticUnitScanner.idl',
 ]
 
-MODULE = 'lwbrk'
+XPIDL_MODULE = 'lwbrk'
 
diff --git a/intl/strres/public/moz.build b/intl/strres/public/moz.build
index e5659cde3b7c85..a614068cd69faa 100644
--- a/intl/strres/public/moz.build
+++ b/intl/strres/public/moz.build
@@ -9,5 +9,5 @@ XPIDL_SOURCES += [
     'nsIStringBundleOverride.idl',
 ]
 
-MODULE = 'intl'
+XPIDL_MODULE = 'intl'
 
diff --git a/intl/uconv/idl/moz.build b/intl/uconv/idl/moz.build
index 5ea28d6dbfd23c..87a2b445733cf7 100644
--- a/intl/uconv/idl/moz.build
+++ b/intl/uconv/idl/moz.build
@@ -12,5 +12,5 @@ XPIDL_SOURCES += [
     'nsIUTF8ConverterService.idl',
 ]
 
-MODULE = 'uconv'
+XPIDL_MODULE = 'uconv'
 
diff --git a/intl/unicharutil/idl/moz.build b/intl/unicharutil/idl/moz.build
index e1c83a77c425b8..186b85dddd8ad8 100644
--- a/intl/unicharutil/idl/moz.build
+++ b/intl/unicharutil/idl/moz.build
@@ -10,5 +10,5 @@ XPIDL_SOURCES += [
     'nsIUnicodeNormalizer.idl',
 ]
 
-MODULE = 'unicharutil'
+XPIDL_MODULE = 'unicharutil'
 
diff --git a/js/ductwork/debugger/moz.build b/js/ductwork/debugger/moz.build
index 95bae02587cdf2..8f89f39fc702fe 100644
--- a/js/ductwork/debugger/moz.build
+++ b/js/ductwork/debugger/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'IJSDebugger.idl',
 ]
 
-MODULE = 'jsdebugger'
+XPIDL_MODULE = 'jsdebugger'
 
 XPCSHELL_TESTS_MANIFESTS += ['tests/xpcshell.ini']
 
diff --git a/js/xpconnect/idl/moz.build b/js/xpconnect/idl/moz.build
index 9c1e588a92bcb2..d878172040b608 100644
--- a/js/xpconnect/idl/moz.build
+++ b/js/xpconnect/idl/moz.build
@@ -20,5 +20,5 @@ XPIDL_SOURCES += [
     'xpcjsid.idl',
 ]
 
-MODULE = 'xpconnect'
+XPIDL_MODULE = 'xpconnect'
 
diff --git a/js/xpconnect/tests/idl/moz.build b/js/xpconnect/tests/idl/moz.build
index e5ff90df2fd8ec..183fc239a491e2 100644
--- a/js/xpconnect/tests/idl/moz.build
+++ b/js/xpconnect/tests/idl/moz.build
@@ -11,5 +11,5 @@ XPIDL_SOURCES += [
     'xpctest_params.idl',
 ]
 
-MODULE = 'xpctest'
+XPIDL_MODULE = 'xpctest'
 
diff --git a/layout/inspector/public/moz.build b/layout/inspector/public/moz.build
index 38f6da45f91885..c92350bdd2da39 100644
--- a/layout/inspector/public/moz.build
+++ b/layout/inspector/public/moz.build
@@ -16,5 +16,5 @@ XPIDL_SOURCES += [
     'nsIDOMFontFaceList.idl',
 ]
 
-MODULE = 'inspector'
+XPIDL_MODULE = 'inspector'
 
diff --git a/layout/tools/layout-debug/src/moz.build b/layout/tools/layout-debug/src/moz.build
index 482fbebbfe379a..340aa269f63bcb 100644
--- a/layout/tools/layout-debug/src/moz.build
+++ b/layout/tools/layout-debug/src/moz.build
@@ -9,7 +9,7 @@ XPIDL_SOURCES += [
     'nsILayoutRegressionTester.idl',
 ]
 
-MODULE = 'layout_debug'
+XPIDL_MODULE = 'layout_debug'
 
 EXPORTS += [
     'nsLayoutDebugCIID.h',
diff --git a/mobile/android/components/build/moz.build b/mobile/android/components/build/moz.build
index 3f13f525f09f69..cff612186fc038 100644
--- a/mobile/android/components/build/moz.build
+++ b/mobile/android/components/build/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'nsIShellService.idl',
 ]
 
-MODULE = 'browsercomps'
+XPIDL_MODULE = 'browsercomps'
 
 EXPORTS += [
     'nsBrowserComponents.h',
diff --git a/mobile/android/components/moz.build b/mobile/android/components/moz.build
index 78ed968f1b6d40..4092b7ede1ab97 100644
--- a/mobile/android/components/moz.build
+++ b/mobile/android/components/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'SessionStore.idl',
 ]
 
-MODULE = 'MobileComponents'
+XPIDL_MODULE = 'MobileComponents'
 
 EXTRA_COMPONENTS += [
     'AddonUpdateService.js',
diff --git a/modules/libjar/moz.build b/modules/libjar/moz.build
index 5def95b87cba8b..853356dce3eee6 100644
--- a/modules/libjar/moz.build
+++ b/modules/libjar/moz.build
@@ -16,7 +16,7 @@ XPIDL_SOURCES += [
     'nsIZipReader.idl',
 ]
 
-MODULE = 'jar'
+XPIDL_MODULE = 'jar'
 LIBRARY_NAME	= 'jar'
 
 EXPORTS += [
diff --git a/modules/libjar/zipwriter/public/moz.build b/modules/libjar/zipwriter/public/moz.build
index 2b5f90f3441a28..193d8cef81b8dc 100644
--- a/modules/libjar/zipwriter/public/moz.build
+++ b/modules/libjar/zipwriter/public/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'nsIZipWriter.idl',
 ]
 
-MODULE = 'zipwriter'
+XPIDL_MODULE = 'zipwriter'
 
diff --git a/modules/libpref/public/moz.build b/modules/libpref/public/moz.build
index 4a25cf31c5c553..0ba943501656ee 100644
--- a/modules/libpref/public/moz.build
+++ b/modules/libpref/public/moz.build
@@ -13,7 +13,7 @@ XPIDL_SOURCES += [
     'nsIRelativeFilePref.idl',
 ]
 
-MODULE = 'pref'
+XPIDL_MODULE = 'pref'
 
 EXPORTS.mozilla += [
     'Preferences.h',
diff --git a/netwerk/base/public/moz.build b/netwerk/base/public/moz.build
index fcb43c92ff2394..5f1780886f488a 100644
--- a/netwerk/base/public/moz.build
+++ b/netwerk/base/public/moz.build
@@ -125,7 +125,7 @@ if CONFIG['MOZ_TOOLKIT_SEARCH']:
         'nsIBrowserSearchService.idl',
     ]
 
-MODULE = 'necko'
+XPIDL_MODULE = 'necko'
 
 EXPORTS += [
     'netCore.h',
diff --git a/netwerk/mime/moz.build b/netwerk/mime/moz.build
index 634aaddbf7f23a..534d8010eb63df 100644
--- a/netwerk/mime/moz.build
+++ b/netwerk/mime/moz.build
@@ -10,7 +10,7 @@ XPIDL_SOURCES += [
     'nsIMIMEService.idl',
 ]
 
-MODULE = 'mimetype'
+XPIDL_MODULE = 'mimetype'
 
 EXPORTS += [
     'nsMimeTypes.h',
diff --git a/netwerk/test/httpserver/moz.build b/netwerk/test/httpserver/moz.build
index b199a1ba41e2ee..a2e178b76dc51d 100644
--- a/netwerk/test/httpserver/moz.build
+++ b/netwerk/test/httpserver/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'nsIHttpServer.idl',
 ]
 
-MODULE = 'test_necko'
+XPIDL_MODULE = 'test_necko'
 
 XPCSHELL_TESTS_MANIFESTS += ['test/xpcshell.ini']
 
diff --git a/parser/html/moz.build b/parser/html/moz.build
index a9f316ceec708c..7a3565a6e9c58b 100644
--- a/parser/html/moz.build
+++ b/parser/html/moz.build
@@ -9,7 +9,7 @@ XPIDL_SOURCES += [
     'nsIScriptableUnescapeHTML.idl',
 ]
 
-MODULE = 'html5'
+XPIDL_MODULE = 'html5'
 
 EXPORTS += [
     'jArray.h',
diff --git a/parser/htmlparser/public/moz.build b/parser/htmlparser/public/moz.build
index 151b171c675166..9ff00f397430a7 100644
--- a/parser/htmlparser/public/moz.build
+++ b/parser/htmlparser/public/moz.build
@@ -9,7 +9,7 @@ XPIDL_SOURCES += [
     'nsIExtendedExpatSink.idl',
 ]
 
-MODULE = 'htmlparser'
+XPIDL_MODULE = 'htmlparser'
 
 EXPORTS += [
     'nsHTMLTagList.h',
diff --git a/profile/public/moz.build b/profile/public/moz.build
index 891df984b51ff6..5ba881bfcd7167 100644
--- a/profile/public/moz.build
+++ b/profile/public/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'nsIProfileUnlocker.idl',
 ]
 
-MODULE = 'profile'
+XPIDL_MODULE = 'profile'
 
diff --git a/rdf/base/idl/moz.build b/rdf/base/idl/moz.build
index fbaea3cdf5bf69..f78f1ab34ae6ea 100644
--- a/rdf/base/idl/moz.build
+++ b/rdf/base/idl/moz.build
@@ -29,5 +29,5 @@ XPIDL_SOURCES += [
     'rdfITripleVisitor.idl',
 ]
 
-MODULE = 'rdf'
+XPIDL_MODULE = 'rdf'
 
diff --git a/security/manager/boot/public/moz.build b/security/manager/boot/public/moz.build
index 981bcfa0fc09ff..03601ec833d009 100644
--- a/security/manager/boot/public/moz.build
+++ b/security/manager/boot/public/moz.build
@@ -11,5 +11,5 @@ XPIDL_SOURCES += [
     'nsISSLStatusProvider.idl',
 ]
 
-MODULE = 'pipboot'
+XPIDL_MODULE = 'pipboot'
 
diff --git a/security/manager/pki/public/moz.build b/security/manager/pki/public/moz.build
index 2df60d4081f398..b9a8d9528cdd76 100644
--- a/security/manager/pki/public/moz.build
+++ b/security/manager/pki/public/moz.build
@@ -9,5 +9,5 @@ XPIDL_SOURCES += [
     'nsIPKIParamBlock.idl',
 ]
 
-MODULE = 'pippki'
+XPIDL_MODULE = 'pippki'
 
diff --git a/security/manager/ssl/public/moz.build b/security/manager/ssl/public/moz.build
index bbe4ad0f5d0970..96b8383c6fdd2e 100644
--- a/security/manager/ssl/public/moz.build
+++ b/security/manager/ssl/public/moz.build
@@ -61,5 +61,5 @@ if CONFIG['MOZ_XUL']:
         'nsICertTree.idl',
     ]
 
-MODULE = 'pipnss'
+XPIDL_MODULE = 'pipnss'
 
diff --git a/startupcache/moz.build b/startupcache/moz.build
index f8151578d4a06c..6d97069d0ca94c 100644
--- a/startupcache/moz.build
+++ b/startupcache/moz.build
@@ -11,7 +11,7 @@ XPIDL_SOURCES += [
     'nsIStartupCache.idl',
 ]
 
-MODULE = 'startupcache'
+XPIDL_MODULE = 'startupcache'
 
 EXPORTS.mozilla.scache += [
     'StartupCache.h',
diff --git a/storage/public/moz.build b/storage/public/moz.build
index 6343f7a0473d13..f99dc162618b50 100644
--- a/storage/public/moz.build
+++ b/storage/public/moz.build
@@ -28,7 +28,7 @@ XPIDL_SOURCES += [
     'mozIStorageValueArray.idl',
 ]
 
-MODULE = 'storage'
+XPIDL_MODULE = 'storage'
 
 EXPORTS += [
     'mozStorageHelper.h',
diff --git a/toolkit/components/alerts/moz.build b/toolkit/components/alerts/moz.build
index cb3cbcec4dfc5c..55ffef8366154e 100644
--- a/toolkit/components/alerts/moz.build
+++ b/toolkit/components/alerts/moz.build
@@ -10,7 +10,7 @@ XPIDL_SOURCES += [
     'nsIAlertsService.idl',
 ]
 
-MODULE = 'alerts'
+XPIDL_MODULE = 'alerts'
 
 SOURCES += [
     'nsAlertsService.cpp',
diff --git a/toolkit/components/autocomplete/moz.build b/toolkit/components/autocomplete/moz.build
index 8322d39a21160f..b1a69a7cc72daf 100644
--- a/toolkit/components/autocomplete/moz.build
+++ b/toolkit/components/autocomplete/moz.build
@@ -15,7 +15,7 @@ XPIDL_SOURCES += [
     'nsIAutoCompleteSimpleResult.idl',
 ]
 
-MODULE = 'autocomplete'
+XPIDL_MODULE = 'autocomplete'
 
 SOURCES += [
     'nsAutoCompleteController.cpp',
diff --git a/toolkit/components/captivedetect/moz.build b/toolkit/components/captivedetect/moz.build
index c7b510f3ffe0e7..ec029640c589b8 100644
--- a/toolkit/components/captivedetect/moz.build
+++ b/toolkit/components/captivedetect/moz.build
@@ -10,7 +10,7 @@ XPIDL_SOURCES += [
     'nsICaptivePortalDetector.idl',
 ]
 
-MODULE = 'captivedetect'
+XPIDL_MODULE = 'captivedetect'
 
 EXTRA_COMPONENTS += [
     'captivedetect.js',
diff --git a/toolkit/components/diskspacewatcher/moz.build b/toolkit/components/diskspacewatcher/moz.build
index d093efdaaac9c2..070324b59a56f8 100644
--- a/toolkit/components/diskspacewatcher/moz.build
+++ b/toolkit/components/diskspacewatcher/moz.build
@@ -13,7 +13,7 @@ EXPORTS += [
 ]
 
 XPIDL_MODULE = 'diskspacewatcher'
-MODULE = 'toolkitcomps'
+XPIDL_MODULE = 'toolkitcomps'
 
 SOURCES = [
     'DiskSpaceWatcher.cpp',
diff --git a/toolkit/components/downloads/moz.build b/toolkit/components/downloads/moz.build
index 4487af8ed22c2f..fc8e4623eb0b05 100644
--- a/toolkit/components/downloads/moz.build
+++ b/toolkit/components/downloads/moz.build
@@ -14,7 +14,7 @@ XPIDL_SOURCES += [
     'nsIDownloadProgressListener.idl',
 ]
 
-MODULE = 'downloads'
+XPIDL_MODULE = 'downloads'
 
 SOURCES += [
     'nsDownloadManager.cpp',
diff --git a/toolkit/components/exthelper/moz.build b/toolkit/components/exthelper/moz.build
index 89bc113cd8a788..f2d768d2af0ec1 100644
--- a/toolkit/components/exthelper/moz.build
+++ b/toolkit/components/exthelper/moz.build
@@ -8,5 +8,5 @@ XPIDL_SOURCES += [
     'extIApplication.idl',
 ]
 
-MODULE = 'exthelper'
+XPIDL_MODULE = 'exthelper'
 
diff --git a/toolkit/components/feeds/moz.build b/toolkit/components/feeds/moz.build
index 9ddd106656261a..e22a5d4593ddb5 100644
--- a/toolkit/components/feeds/moz.build
+++ b/toolkit/components/feeds/moz.build
@@ -19,7 +19,7 @@ XPIDL_SOURCES += [
     'nsIFeedTextConstruct.idl',
 ]
 
-MODULE = 'feeds'
+XPIDL_MODULE = 'feeds'
 
 EXTRA_COMPONENTS += [
     'FeedProcessor.js',
diff --git a/toolkit/components/filepicker/moz.build b/toolkit/components/filepicker/moz.build
index 3fc412c4612be8..5c38ab487b203d 100644
--- a/toolkit/components/filepicker/moz.build
+++ b/toolkit/components/filepicker/moz.build
@@ -7,7 +7,7 @@
 if CONFIG['MOZ_XUL'] and \
     CONFIG['MOZ_WIDGET_TOOLKIT'] not in ('android', 'qt', 'os2', 'cocoa', 'windows'):
         LIBXUL_LIBRARY = True
-        MODULE = 'filepicker'
+        XPIDL_MODULE = 'filepicker'
         LIBRARY_NAME = 'fileview'
         XPIDL_SOURCES += [
             'nsIFileView.idl',
diff --git a/toolkit/components/find/moz.build b/toolkit/components/find/moz.build
index 872acb44fec070..e62ffe511b5d4f 100644
--- a/toolkit/components/find/moz.build
+++ b/toolkit/components/find/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'nsIFindService.idl',
 ]
 
-MODULE = 'mozfind'
+XPIDL_MODULE = 'mozfind'
 
 SOURCES += [
     'nsFindService.cpp',
diff --git a/toolkit/components/jsdownloads/public/moz.build b/toolkit/components/jsdownloads/public/moz.build
index 44a54264c40e75..6ea66bf5f29600 100644
--- a/toolkit/components/jsdownloads/public/moz.build
+++ b/toolkit/components/jsdownloads/public/moz.build
@@ -2,7 +2,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-MODULE = 'jsdownloads'
+XPIDL_MODULE = 'jsdownloads'
 
 XPIDL_SOURCES += [
     'mozIDownloadPlatform.idl',
diff --git a/toolkit/components/parentalcontrols/moz.build b/toolkit/components/parentalcontrols/moz.build
index 27a13d3c10e587..ff80a2ef17d094 100644
--- a/toolkit/components/parentalcontrols/moz.build
+++ b/toolkit/components/parentalcontrols/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'nsIParentalControlsService.idl',
 ]
 
-MODULE = 'parentalcontrols'
+XPIDL_MODULE = 'parentalcontrols'
 
 if not CONFIG['MOZ_DISABLE_PARENTAL_CONTROLS'] and CONFIG['OS_ARCH'] == 'WINNT':
     LIBXUL_LIBRARY = True
diff --git a/toolkit/components/passwordmgr/moz.build b/toolkit/components/passwordmgr/moz.build
index df49c9e042ab06..88b5636d6b1563 100644
--- a/toolkit/components/passwordmgr/moz.build
+++ b/toolkit/components/passwordmgr/moz.build
@@ -15,7 +15,7 @@ XPIDL_SOURCES += [
     'nsILoginMetaInfo.idl',
 ]
 
-MODULE = 'loginmgr'
+XPIDL_MODULE = 'loginmgr'
 
 EXTRA_COMPONENTS += [
     'crypto-SDR.js',
diff --git a/toolkit/components/places/moz.build b/toolkit/components/places/moz.build
index a3b60326af6475..fc1a07d16f28b1 100644
--- a/toolkit/components/places/moz.build
+++ b/toolkit/components/places/moz.build
@@ -11,7 +11,7 @@ XPIDL_SOURCES += [
     'nsINavHistoryService.idl',
 ]
 
-MODULE = 'places'
+XPIDL_MODULE = 'places'
 
 if CONFIG['MOZ_PLACES']:
     LIBXUL_LIBRARY = True
diff --git a/toolkit/components/satchel/moz.build b/toolkit/components/satchel/moz.build
index 985db546551a66..b20e2c0519d26b 100644
--- a/toolkit/components/satchel/moz.build
+++ b/toolkit/components/satchel/moz.build
@@ -13,7 +13,7 @@ XPIDL_SOURCES += [
     'nsIInputListAutoComplete.idl',
 ]
 
-MODULE = 'satchel'
+XPIDL_MODULE = 'satchel'
 
 SOURCES += [
     'nsFormFillController.cpp',
diff --git a/toolkit/components/telemetry/moz.build b/toolkit/components/telemetry/moz.build
index 68c1b0ce8dc1f6..3570145cbb3c25 100644
--- a/toolkit/components/telemetry/moz.build
+++ b/toolkit/components/telemetry/moz.build
@@ -11,7 +11,7 @@ XPIDL_SOURCES += [
     'nsITelemetryPing.idl',
 ]
 
-MODULE = 'telemetry'
+XPIDL_MODULE = 'telemetry'
 
 EXPORTS.mozilla += [
     'ProcessedStack.h',
diff --git a/toolkit/components/typeaheadfind/moz.build b/toolkit/components/typeaheadfind/moz.build
index 8c3a6cbd186c25..71ce3177f841f7 100644
--- a/toolkit/components/typeaheadfind/moz.build
+++ b/toolkit/components/typeaheadfind/moz.build
@@ -8,7 +8,7 @@ XPIDL_SOURCES += [
     'nsITypeAheadFind.idl',
 ]
 
-MODULE = 'fastfind'
+XPIDL_MODULE = 'fastfind'
 
 SOURCES += [
     'nsTypeAheadFind.cpp',
diff --git a/toolkit/components/url-classifier/moz.build b/toolkit/components/url-classifier/moz.build
index 1c8e534d7d37c4..1ac01621327a80 100644
--- a/toolkit/components/url-classifier/moz.build
+++ b/toolkit/components/url-classifier/moz.build
@@ -15,7 +15,7 @@ XPIDL_SOURCES += [
     'nsIUrlListManager.idl',
 ]
 
-MODULE = 'url-classifier'
+XPIDL_MODULE = 'url-classifier'
 
 SOURCES += [
     'ChunkSet.cpp',
diff --git a/toolkit/components/urlformatter/moz.build b/toolkit/components/urlformatter/moz.build
index 7478b7726b8fb7..4a57697b77d607 100644
--- a/toolkit/components/urlformatter/moz.build
+++ b/toolkit/components/urlformatter/moz.build
@@ -10,7 +10,7 @@ XPIDL_SOURCES += [
     'nsIURLFormatter.idl',
 ]
 
-MODULE = 'urlformatter'
+XPIDL_MODULE = 'urlformatter'
 
 EXTRA_COMPONENTS += [
     'nsURLFormatter.manifest',
diff --git a/toolkit/devtools/server/moz.build b/toolkit/devtools/server/moz.build
index d987ac7b8b3585..24b3a7c8aedb15 100644
--- a/toolkit/devtools/server/moz.build
+++ b/toolkit/devtools/server/moz.build
@@ -10,7 +10,7 @@ XPIDL_SOURCES += [
     'nsIJSInspector.idl',
 ]
 
-MODULE = 'jsinspector'
+XPIDL_MODULE = 'jsinspector'
 
 SOURCES += [
     'nsJSInspector.cpp',
diff --git a/toolkit/identity/moz.build b/toolkit/identity/moz.build
index c2babe64bd4b9c..63796a2772762d 100644
--- a/toolkit/identity/moz.build
+++ b/toolkit/identity/moz.build
@@ -10,7 +10,7 @@ XPIDL_SOURCES += [
     'nsIIdentityCryptoService.idl',
 ]
 
-MODULE = 'identity'
+XPIDL_MODULE = 'identity'
 
 SOURCES += [
     'IdentityCryptoService.cpp',
diff --git a/toolkit/mozapps/extensions/moz.build b/toolkit/mozapps/extensions/moz.build
index fdbfd155fe7707..0265ede7ce689b 100644
--- a/toolkit/mozapps/extensions/moz.build
+++ b/toolkit/mozapps/extensions/moz.build
@@ -13,7 +13,7 @@ XPIDL_SOURCES += [
     'amIWebInstallListener.idl',
 ]
 
-MODULE = 'extensions'
+XPIDL_MODULE = 'extensions'
 
 EXTRA_COMPONENTS += [
     'addonManager.js',
diff --git a/toolkit/mozapps/update/moz.build b/toolkit/mozapps/update/moz.build
index 581740c9faea9e..db2f1907542832 100644
--- a/toolkit/mozapps/update/moz.build
+++ b/toolkit/mozapps/update/moz.build
@@ -17,7 +17,7 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'android':
     if CONFIG['MOZ_UPDATER']:
         DIRS += ['updater']
 
-MODULE = 'update'
+XPIDL_MODULE = 'update'
 
 XPCSHELL_TESTS_MANIFESTS += ['tests/unit_timermanager/xpcshell.ini']
 
diff --git a/toolkit/xre/moz.build b/toolkit/xre/moz.build
index 9d9c295eb0de52..e098afc7310403 100644
--- a/toolkit/xre/moz.build
+++ b/toolkit/xre/moz.build
@@ -15,7 +15,7 @@ if CONFIG['OS_ARCH'] == 'WINNT':
         'nsIWinAppHelper.idl',
     ]
 
-MODULE = 'xulapp'
+XPIDL_MODULE = 'xulapp'
 
 if CONFIG['MOZ_INSTRUMENT_EVENT_LOOP']:
     EXPORTS += ['EventTracer.h']
diff --git a/tools/profiler/moz.build b/tools/profiler/moz.build
index 05280460f49169..ae869946440e62 100644
--- a/tools/profiler/moz.build
+++ b/tools/profiler/moz.build
@@ -9,7 +9,7 @@ if CONFIG['MOZ_ENABLE_PROFILER_SPS']:
 
     LIBXUL_LIBRARY = True
 
-    MODULE = 'profiler'
+    XPIDL_MODULE = 'profiler'
     LIBRARY_NAME = 'profiler'
     XPIDL_SOURCES += [
         'nsIProfiler.idl',
diff --git a/uriloader/base/moz.build b/uriloader/base/moz.build
index 6c761fc61992c7..7200eef903d09f 100644
--- a/uriloader/base/moz.build
+++ b/uriloader/base/moz.build
@@ -16,7 +16,7 @@ XPIDL_SOURCES += [
     'nsIWebProgressListener2.idl',
 ]
 
-MODULE = 'uriloader'
+XPIDL_MODULE = 'uriloader'
 
 EXPORTS += [
     'nsDocLoader.h',
diff --git a/uriloader/exthandler/moz.build b/uriloader/exthandler/moz.build
index e9207d54fa24eb..277dbe563c4fea 100644
--- a/uriloader/exthandler/moz.build
+++ b/uriloader/exthandler/moz.build
@@ -17,7 +17,7 @@ XPIDL_SOURCES += [
     'nsIHelperAppLauncherDialog.idl',
 ]
 
-MODULE = 'exthandler'
+XPIDL_MODULE = 'exthandler'
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'os2':
     osdir = 'os2'
diff --git a/uriloader/prefetch/moz.build b/uriloader/prefetch/moz.build
index ebac711b447e32..3a0066f56e1891 100644
--- a/uriloader/prefetch/moz.build
+++ b/uriloader/prefetch/moz.build
@@ -9,7 +9,7 @@ XPIDL_SOURCES += [
     'nsIPrefetchService.idl',
 ]
 
-MODULE = 'prefetch'
+XPIDL_MODULE = 'prefetch'
 
 EXPORTS += [
     'nsCPrefetchService.h',
diff --git a/widget/moz.build b/widget/moz.build
index 17b2c6e295d34d..3f19d324c32983 100644
--- a/widget/moz.build
+++ b/widget/moz.build
@@ -95,7 +95,7 @@ if CONFIG['MOZ_METRO']:
         'nsIWinMetroUtils.idl',
     ]
 
-MODULE = 'widget'
+XPIDL_MODULE = 'widget'
 
 EXPORTS += [
     'InputData.h',
diff --git a/xpcom/sample/moz.build b/xpcom/sample/moz.build
index b9c0c90bd16dab..9229070cca4bc6 100644
--- a/xpcom/sample/moz.build
+++ b/xpcom/sample/moz.build
@@ -12,9 +12,9 @@ TEST_TOOL_DIRS += ['program']
 # on these files to generate C++ headers and .xpt typelib files.
 XPIDL_SOURCES += ['nsISample.idl']
 
-# MODULE specifies where header files from this Makefile are installed,
+# XPIDL_MODULE specifies where header files from this Makefile are installed,
 # i.e. dist/include/xpcomsample
-MODULE = 'xpcomsample'
+XPIDL_MODULE = 'xpcomsample'
 
 # CPP_SOURCES specifies C++ files to be built into a library.
 SOURCES += [
diff --git a/xpfe/appshell/public/moz.build b/xpfe/appshell/public/moz.build
index 8cd054a60cfc49..c96139567d1c51 100644
--- a/xpfe/appshell/public/moz.build
+++ b/xpfe/appshell/public/moz.build
@@ -13,7 +13,7 @@ XPIDL_SOURCES += [
     'nsIXULWindow.idl',
 ]
 
-MODULE = 'appshell'
+XPIDL_MODULE = 'appshell'
 
 EXPORTS += [
     'nsAppShellCID.h',
diff --git a/xulrunner/examples/simple/components/public/moz.build b/xulrunner/examples/simple/components/public/moz.build
index 96d626d82807ec..3a611f85ac632e 100644
--- a/xulrunner/examples/simple/components/public/moz.build
+++ b/xulrunner/examples/simple/components/public/moz.build
@@ -8,6 +8,6 @@ XPIDL_SOURCES += [
     'nsISimpleTest.idl',
 ]
 
-MODULE = 'simple'
+XPIDL_MODULE = 'simple'
 
 XPI_NAME = 'simple'