diff --git a/ChangeLog b/ChangeLog
index 92849f62f..21fef9fe6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2007-12-21  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/GSLocale.m: protect locale access with locks.
+
 2007-12-21  David Ayers  <ayers@fsfe.org>
 
 	* Source/NSPathUtilities.m (_POSIX_PTHREAD_SEMANTICS): Define to expose
diff --git a/Source/GSLocale.m b/Source/GSLocale.m
index 6d0e1b3b6..88addf522 100644
--- a/Source/GSLocale.m
+++ b/Source/GSLocale.m
@@ -108,6 +108,11 @@ GSDomainFromDefaultLocale(void)
 
   dict = [NSMutableDictionary dictionary];
 
+  /* Protect locale access with locks to prevent multiple threads using
+   * it and interfering with the buffer.
+   */
+  [gnustep_global_lock lock];
+
 #ifdef HAVE_LANGINFO_H
   /* Time/Date Information */
   arr = [NSMutableArray arrayWithCapacity: 7];
@@ -189,7 +194,6 @@ GSDomainFromDefaultLocale(void)
 	       forKey: NSThousandsSeparator];
     }
 
-
   /* FIXME: Get currency format from localeconv */
 
 #ifdef	LC_MESSAGES
@@ -207,7 +211,6 @@ GSDomainFromDefaultLocale(void)
       [dict setObject: str2 forKey: NSLanguageName];
     }
 
-  [gnustep_global_lock lock];
   /*
    * Another thread might have been faster in setting the static variable.
    * If so, we just drop our dict.
diff --git a/Source/NSUserDefaults.m b/Source/NSUserDefaults.m
index 470df9daf..bbf43dda2 100644
--- a/Source/NSUserDefaults.m
+++ b/Source/NSUserDefaults.m
@@ -266,14 +266,20 @@ static BOOL setSharedDefaults = NO;     /* Flag to prevent infinite recursion */
     {
       NSDictionary	*regDefs;
 
-      [sharedDefaults synchronize];	// Ensure changes are written.
-      regDefs = RETAIN([sharedDefaults->_tempDomains
-	objectForKey: NSRegistrationDomain]);
       /* To ensure that we don't try to synchronise the old defaults to disk
        * after creating the new ones, remove as housekeeping notification
        * observer.
        */
       [[NSNotificationCenter defaultCenter] removeObserver: sharedDefaults];
+
+      /* Ensure changes are written, and no changes left so we can't end up
+       * writing old changes to the new defaults.
+       */
+      [sharedDefaults synchronize];
+      DESTROY(sharedDefaults->_changedDomains);
+
+      regDefs = RETAIN([sharedDefaults->_tempDomains
+	objectForKey: NSRegistrationDomain]);
       setSharedDefaults = NO;
       DESTROY(sharedDefaults);
       if (regDefs != nil)