diff --git a/IcedTeaPlugin.cc b/IcedTeaPlugin.cc
index a88cb6c..7acb7dc 100644
--- a/IcedTeaPlugin.cc
+++ b/IcedTeaPlugin.cc
@@ -3824,6 +3824,8 @@ void IcedTeaPluginFactory::IcedTeaPluginFactory::WriteToJVM(nsCString& message)
 
 */
 
+#include <nsIInterfaceInfoManager.h>
+
 nsresult
 IcedTeaPluginFactory::StartAppletviewer ()
 {
@@ -3845,9 +3847,15 @@ IcedTeaPluginFactory::StartAppletviewer ()
   result = file->InitWithNativePath (nsCString (appletviewer_executable));
   PLUGIN_CHECK_RETURN ("init with path", result);
 
+  // run-time query provided through nsIInterfaceInfoManager
+  nsCOMPtr<nsIInterfaceInfoManager> iim(do_GetService(NS_INTERFACEINFOMANAGER_SERVICE_CONTRACTID));
+  // get the run-time IID of nsIProcess (don't rely on a the build-time IID)
+  nsIID *nsIProcessIID;
+  iim->GetIIDForName("nsIProcess", &nsIProcessIID);
+
   result = manager->CreateInstanceByContractID (NS_PROCESS_CONTRACTID,
                                                 nsnull,
-                                                NS_GET_IID (nsIProcess),
+                                                *nsIProcessIID,
                                                 getter_AddRefs (applet_viewer_process));
   PLUGIN_CHECK_RETURN ("create process", result);