diff --git a/HISTORY b/HISTORY
index 83b13aca..2572b44b 100644
--- a/HISTORY
+++ b/HISTORY
@@ -3987,3 +3987,5 @@ Video Disk Recorder Revision History
 - Fixed a possible crash when displaying the "Low disk space!" message from
   a background thread (thanks to Christof Steininger).
 - Fixed handling OSD areas that have invalid sizes (thanks to Marco Schlüßler).
+- Added a mutex to AssertFreeDiskSpace() to make sure calls from foreground
+  and background threads won't interfere.
diff --git a/recording.c b/recording.c
index 61098095..5cf769f4 100644
--- a/recording.c
+++ b/recording.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: recording.c 1.127 2005/12/18 12:37:10 kls Exp $
+ * $Id: recording.c 1.128 2005/12/18 13:09:47 kls Exp $
  */
 
 #include "recording.h"
@@ -84,6 +84,8 @@ void RemoveDeletedRecordings(void)
 
 void AssertFreeDiskSpace(int Priority)
 {
+  static cMutex Mutex;
+  cMutexLock MutexLock(&Mutex);
   // With every call to this function we try to actually remove
   // a file, or mark a file for removal ("delete" it), so that
   // it will get removed during the next call.