diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 1767899e..adbd0cad 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -921,6 +921,7 @@ Ludwig Nussel <ludwig.nussel@web.de>
  for adding some missing 'const' keywords
  for pointing out that "%016llX" should be used instead of "%016LX"
  for adding some missing 'const' keywords to avoid compilation errors with gcc 4.4
+ for reporting that cSVDRP::CmdGRAB() writes into const data
 
 Thomas Koch <tom@harhar.net>
  for his support in keeping the Premiere World channels up to date in 'channels.conf'
diff --git a/HISTORY b/HISTORY
index 29b7ed60..4f75111f 100644
--- a/HISTORY
+++ b/HISTORY
@@ -6127,3 +6127,5 @@ Video Disk Recorder Revision History
   Reinhard Nissl).
 - Added some missing 'const' keywords to avoid compilation errors with gcc 4.4
   (thanks to Ville Skyttä and Ludwig Nussel).
+- Modified cSVDRP::CmdGRAB() to avoid writing into const data (reported by
+  Ludwig Nussel).
diff --git a/svdrp.c b/svdrp.c
index b417a8e1..416b8698 100644
--- a/svdrp.c
+++ b/svdrp.c
@@ -10,7 +10,7 @@
  * and interact with the Video Disk Recorder - or write a full featured
  * graphical interface that sits on top of an SVDRP connection.
  *
- * $Id: svdrp.c 2.4 2009/06/06 13:42:52 kls Exp $
+ * $Id: svdrp.c 2.5 2009/06/06 14:03:55 kls Exp $
  */
 
 #include "svdrp.h"
@@ -798,16 +798,17 @@ void cSVDRP::CmdGRAB(const char *Option)
      char RealFileName[PATH_MAX];
      if (FileName) {
         if (grabImageDir) {
-           cString s;
-           char *slash = strrchr(FileName, '/');
+           cString s(FileName);
+           FileName = s;
+           const char *slash = strrchr(FileName, '/');
            if (!slash) {
               s = AddDirectory(grabImageDir, FileName);
               FileName = s;
               }
            slash = strrchr(FileName, '/'); // there definitely is one
-           *slash = 0;
-           char *r = realpath(FileName, RealFileName);
-           *slash = '/';
+           cString t(s);
+           t.Truncate(slash - FileName);
+           char *r = realpath(t, RealFileName);
            if (!r) {
               LOG_ERROR_STR(FileName);
               Reply(501, "Invalid file name \"%s\"", FileName);