diff --git a/ChangeLog b/ChangeLog
index b163629a5..0171732d6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-07-26  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/Additions/NSObject+GNUstepbase.m: use separate lock to
+	protect at exit methods ... avoid conflict/deadlock with multithreaded
+	notification change.
+
 2016-07-18  Larry Campbell <lcampbel@akamai.com>
 
 	* Source/NSThread.m: Send notification about becoming multithreaded
diff --git a/Source/Additions/GSMime.m b/Source/Additions/GSMime.m
index d3230808a..5bfe75eb7 100644
--- a/Source/Additions/GSMime.m
+++ b/Source/Additions/GSMime.m
@@ -123,6 +123,7 @@ static	Class		documentClass = 0;
 static	Class		headerClass = 0;
 
 static BOOL             oldStyleFolding = NO;
+static NSString         *text7bitEncoding = @"quoted-printable";
 
 typedef BOOL (*boolIMP)(id, SEL, id);
 
@@ -4500,6 +4501,14 @@ appendString(NSMutableData *m, NSUInteger offset, NSUInteger fold,
  */
 @implementation	GSMimeDocument
 
++ (void) setText7bitBase64: (BOOL)aFlag
+{
+  if (YES == aFlag)
+    text7bitEncoding = @"base64";
+  else
+    text7bitEncoding = @"quoted-printable";
+}
+
 /*
  * Examine xml data to find out the characterset needed to convert from
  * binary data to an NSString object.
@@ -5776,7 +5785,7 @@ appendString(NSMutableData *m, NSUInteger offset, NSUInteger fold,
 	      if (e != NSASCIIStringEncoding && e != NSUTF7StringEncoding)
 #endif
 		{
-                  v = @"quoted-printable";
+                  v = text7bitEncoding;
                 }
               else
                 {
@@ -6686,7 +6695,7 @@ appendString(NSMutableData *m, NSUInteger offset, NSUInteger fold,
                */
               if (YES == want7Bit)
                 {
-                  encoding = @"quoted-printable";
+                  encoding = text7bitEncoding;
                 }
               enc = [self setHeader: @"Content-Transfer-Encoding"
                               value: encoding
diff --git a/Source/Additions/NSObject+GNUstepBase.m b/Source/Additions/NSObject+GNUstepBase.m
index 71d5e30a4..143436dbe 100644
--- a/Source/Additions/NSObject+GNUstepBase.m
+++ b/Source/Additions/NSObject+GNUstepBase.m
@@ -145,6 +145,20 @@ struct exitLink {
 static struct exitLink	*exited = 0;
 static BOOL		enabled = NO;
 static BOOL		shouldCleanUp = NO;
+static NSLock           *exitLock = nil;
+
+static inline void setup()
+{
+  if (nil == exitLock)
+    {
+      [gnustep_global_lock lock];
+      if (nil == exitLock)
+        {
+          exitLock = [NSLock new];
+        } 
+      [gnustep_global_lock unlock];
+    }
+}
 
 static void
 handleExit()
@@ -197,10 +211,11 @@ handleExit()
   l->at = anAddress;
   l->obj = [*anAddress retain];
   l->sel = 0;
-  [gnustep_global_lock lock];
+  setup();
+  [exitLock lock];
   l->next = exited;
   exited = l;
-  [gnustep_global_lock unlock];
+  [exitLock unlock];
   return l->obj;
 }
 
@@ -212,10 +227,11 @@ handleExit()
   l->at = 0;
   l->obj = [anObject retain];
   l->sel = 0;
-  [gnustep_global_lock lock];
+  setup();
+  [exitLock lock];
   l->next = exited;
   exited = l;
-  [gnustep_global_lock unlock];
+  [exitLock unlock];
   return l->obj;
 }
 
@@ -247,12 +263,13 @@ handleExit()
       return NO;	// method not implemented in this class
     }
 
-  [gnustep_global_lock lock];
+  setup();
+  [exitLock lock];
   for (l = exited; l != 0; l = l->next)
     {
       if (l->obj == self && sel_isEqual(l->sel, sel))
 	{
-	  [gnustep_global_lock unlock];
+	  [exitLock unlock];
 	  return NO;	// Already registered
 	}
     }
@@ -267,7 +284,7 @@ handleExit()
       atexit(handleExit);
       enabled = YES;
     }
-  [gnustep_global_lock unlock];
+  [exitLock unlock];
   return YES;
 }
 
@@ -275,13 +292,14 @@ handleExit()
 {
   if (YES == aFlag)
     {
-      [gnustep_global_lock lock];
+      setup();
+      [exitLock lock];
       if (NO == enabled)
 	{
 	  atexit(handleExit);
 	  enabled = YES;
 	}
-      [gnustep_global_lock unlock];
+      [exitLock unlock];
       shouldCleanUp = YES;
     }
   else