diff --git a/ChangeLog b/ChangeLog
index dc682cc15d..65b54c568f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2006-06-14  Jean-Marc Lasgouttes  <lasgouttes@lyx.org>
+
+	* configure.ac: improve test for zlib.
+
 2006-05-16  Jean-Marc Lasgouttes  <lasgouttes@lyx.org>
 
 	* configure.ac: improve check for shlwapi.
diff --git a/configure.ac b/configure.ac
index c8342879b7..644357bd03 100644
--- a/configure.ac
+++ b/configure.ac
@@ -257,8 +257,8 @@ AC_FUNC_MKDIR
 
 # check for compression support
 AC_CHECK_HEADERS(zlib.h,
- [AC_CHECK_LIB(z, gzopen, [LIBS="$LIBS -lz"], LYX_ERROR([zlib not found!]))],
- [LYX_ERROR([zlib.h not found!])])
+ [AC_CHECK_LIB(z, gzopen, [LIBS="$LIBS -lz"], LYX_LIB_ERROR(libz,zlib))],
+ [LYX_LIB_ERROR(zlib.h,zlib)])
 
 dnl This is a slight hack: the tests generated by autoconf 2.52 do not
 dnl work correctly because of some conflict with stdlib.h with g++ 2.96
diff --git a/src/support/ChangeLog b/src/support/ChangeLog
index 33a803fe00..273ff97ab1 100644
--- a/src/support/ChangeLog
+++ b/src/support/ChangeLog
@@ -1,3 +1,8 @@
+2006-06-14  Jean-Marc Lasgouttes  <lasgouttes@lyx.org>
+
+	* gzstream.h: do not test for HAVE_ZLIB_H, since we require it
+	anyway. 
+
 2006-05-29  Jean-Marc Lasgouttes  <lasgouttes@lyx.org>
 
 	* os_unix.C (canAutoOpenFile, autoOpenFile): add support for Mac
diff --git a/src/support/gzstream.h b/src/support/gzstream.h
index 0adeb62a99..858784dae9 100644
--- a/src/support/gzstream.h
+++ b/src/support/gzstream.h
@@ -32,9 +32,7 @@
 // standard C++ with new header file names and std:: namespace
 #include <iostream>
 #include <fstream>
-#ifdef HAVE_ZLIB_H
-# include <zlib.h>
-#endif
+#include <zlib.h>
 
 // For LyX
 #define GZSTREAM_NAMESPACE gz