diff --git a/src/ChangeLog b/src/ChangeLog
index 001d3909..8db453b0 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2011-11-09  Gijs van Tulder  <address@hidden>
+
+	* warc.c: Call gzdopen() with wb9 instead of wb+9, which fails on
+	zlib version >= 1.2.4.
+
 2011-11-04  Steven Schweda  <address@hidden>
 
 	* warc.c [! WINDOWS]: Include <libgen.h>.
diff --git a/src/warc.c b/src/warc.c
index 33488c4e..680ac997 100644
--- a/src/warc.c
+++ b/src/warc.c
@@ -169,7 +169,7 @@ warc_write_start_record ()
       fflush (warc_current_file);
 
       /* Start a new GZIP stream. */
-      warc_current_gzfile = gzdopen (dup (fileno (warc_current_file)), "wb+9");
+      warc_current_gzfile = gzdopen (dup (fileno (warc_current_file)), "wb9");
       warc_current_gzfile_uncompressed_size = 0;
 
       if (warc_current_gzfile == NULL)