diff --git a/ChangeLog b/ChangeLog
index 02a74f94b..51a233146 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,13 @@
+2013-05-31  Richard Frith-Macdonald <rfm@gnu.org>
+
+        * Source/NSLock.m: ([-lockWhenCondition:beforeDate:])
+        Lock mutex using -lockBeforeDate: so that we can abandon the wait
+        for the condition at the spacified date in the case where we can't
+        even obtain a lock before that date.
+        Fix for bug #39126
+
 2013-05-29 Sebastian Reitenbach <sebastia@l00-bugdead-prods.de>
+
 	* Headers/Foundation/NSString.h
 	  make NSStringEncoding enum typdef to NSUInteger
 	* Source/Additions/Unicode.m
diff --git a/Source/NSLock.m b/Source/NSLock.m
index 3a3294be1..50ef1cd97 100644
--- a/Source/NSLock.m
+++ b/Source/NSLock.m
@@ -404,7 +404,10 @@ MUNLOCK
 - (BOOL) lockWhenCondition: (NSInteger)condition_to_meet
                 beforeDate: (NSDate*)limitDate
 {
-  [_condition lock];
+  if (NO == [_condition lockBeforeDate: limitDate])
+    {
+      return NO;
+    }
   if (condition_to_meet == _condition_value)
     {
       return YES;