diff --git a/src/BrowserWindow.cpp b/src/BrowserWindow.cpp
index f260295..10ae7bd 100755
--- a/src/BrowserWindow.cpp
+++ b/src/BrowserWindow.cpp
@@ -28,23 +28,6 @@
 NS_GENERIC_FACTORY_CONSTRUCTOR(SecurityWarningDialogs)
 NS_GENERIC_FACTORY_CONSTRUCTOR(PromptService)
 
-static const nsModuleComponentInfo components[] = {
-  {
-	SECURITYWARNINGSDIALOGS_CLASSNAME,
-	SECURITYWARNINGSDIALOGS_CID,
-	NS_SECURITYWARNINGDIALOGS_CONTRACTID,
-	SecurityWarningDialogsConstructor
-  },
-  {
-	PROMPTSERVICE_CLASSNAME,
-	PROMPTSERVICE_CID,
-	NS_PROMPTSERVICE_CONTRACTID,
-	PromptServiceConstructor
-  }
-
-};
-
-
 BrowserWindow::BrowserWindow (void)
 {
 	owner = nsnull;
@@ -162,17 +145,17 @@ nsresult BrowserWindow::RegisterComponents ()
     nsCOMPtr<nsIFactory> componentFactory;
     rv = NS_NewSecurityWarningServiceFactory(getter_AddRefs(componentFactory));
     if (NS_SUCCEEDED(rv)) {
-        compReg->RegisterFactory(components[0].mCID,
-                                 components[0].mDescription,
-                                 components[0].mContractID,
+		compReg->RegisterFactory(kSECURITYWARNINGSDIALOGS_CID,
+                                 SECURITYWARNINGSDIALOGS_CLASSNAME,
+                                 NS_SECURITYWARNINGDIALOGS_CONTRACTID,
                                  componentFactory);
 	}
 
     rv = NS_NewPromptServiceFactory(getter_AddRefs(componentFactory), this);
     if (NS_SUCCEEDED(rv)) {
-        compReg->RegisterFactory(components[1].mCID,
-                                 components[1].mDescription,
-                                 components[1].mContractID,
+        compReg->RegisterFactory(kPROMPTSERVICE_CID,
+                                 PROMPTSERVICE_CLASSNAME,
+                                 NS_PROMPTSERVICE_CONTRACTID,
                                  componentFactory);
 	}
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 3b7bce3..cd6ec99 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -26,7 +26,7 @@ libgluezilla_la_SOURCES = 	\
 	gluezilla.h   \
 	FastDelegate.h
 
-if OLDXUL
+if XUL_2
 libgluezilla_la_SOURCES += \
 	gluezilla_nsIScriptContext.h \
 	gluezilla_nsIScriptGlobalObject.h
diff --git a/src/PromptService.h b/src/PromptService.h
index 04fddb9..174bca4 100644
--- a/src/PromptService.h
+++ b/src/PromptService.h
@@ -20,8 +20,9 @@
 // {77686174-2061-6d20-6920-746F20646F20}
 #define PROMPTSERVICE_CID \
 { 0x77686174, 0x2061, 0x6d20, { 0x69, 0x20, 0x74, 0x6F, 0x20, 0x64, 0x6F, 0x20 } }
-
-
+
+static NS_DEFINE_CID(kPROMPTSERVICE_CID, PROMPTSERVICE_CID);
+
 class PromptService : public nsIPromptService
 {
 	NS_DECL_ISUPPORTS
diff --git a/src/SecurityWarningsDialogs.h b/src/SecurityWarningsDialogs.h
index b75f529..ae352ad 100644
--- a/src/SecurityWarningsDialogs.h
+++ b/src/SecurityWarningsDialogs.h
@@ -21,8 +21,9 @@
 // {696E7465-7265-7374-696E-67206C696665}
 #define SECURITYWARNINGSDIALOGS_CID \
 { 0x696E7465, 0x7265, 0x7374, { 0x69, 0x6E, 0x67, 0x20, 0x6C, 0x69, 0x66, 0x65 } }
-
-
+
+static NS_DEFINE_CID(kSECURITYWARNINGSDIALOGS_CID, SECURITYWARNINGSDIALOGS_CID);
+
 class SecurityWarningDialogs : public nsISecurityWarningDialogs
 {
 public:
diff --git a/src/interfaces.h b/src/interfaces.h
index 3a9f9dd..6acebb8 100644
--- a/src/interfaces.h
+++ b/src/interfaces.h
@@ -4,7 +4,18 @@
 #define TO_STRING(x) #x
 
 //Gecko Embedding API
+#if XUL_VERSION < 4
 #include <nsEmbedAPI.h>
+#else
+#include <nscore.h>
+#include <nsXPCOM.h>
+#include <nsILocalFile.h>
+#include <nsIDirectoryService.h>
+#define NS_GRE_COMPONENT_DIR                    "GreComsD"
+#define NS_XPCOM_COMPONENT_DIR                  "ComsD"
+#define NS_XPCOM_COMPONENT_REGISTRY_FILE        "ComRegF"
+#define NS_XPCOM_XPTI_REGISTRY_FILE             "XptiRegF"
+#endif
 
 //XPCOM API
 #include <nsCOMPtr.h>
@@ -78,8 +89,12 @@
 #include <nsIPromptService.h>
 #include <nsISecurityWarningDialogs.h>
 #include <nsIComponentRegistrar.h>
+#if XUL_VERSION < 4
 #include <nsIGenericFactory.h>
-
+#else
+#include <mozilla/ModuleUtils.h>
+struct nsModuleComponentInfo;
+#endif
 // preferences
 #include <nsIPrefBranch.h>
 #include <nsIPrefService.h>
@@ -131,12 +146,15 @@
   typedef type (NS_FROZENCALL * name##Type) params; \
   extern name##Type name NS_HIDDEN;
 
+#if XUL_VERSION < 4
 XRE_API(nsresult,
 	XRE_InitEmbedding, (nsILocalFile *aLibXULDirectory,
 						nsILocalFile *aAppDirectory,
 						nsIDirectoryServiceProvider *aAppDirProvider,
 						nsStaticModuleInfo const *aStaticComponents,
 						PRUint32 aStaticComponentCount))
+#endif
+
 
 XRE_API(void, XRE_TermEmbedding, ())