diff --git a/acinclude-2.1.m4 b/acinclude-2.1.m4
index 85fd6accb..527af2f90 100644
--- a/acinclude-2.1.m4
+++ b/acinclude-2.1.m4
@@ -675,7 +675,7 @@ AC_DEFUN(PATH_EXPAT,
 
   EXPAT_CFLAGS=
   EXPAT_LIBS=
-	if test "$with_expat" != "yes"; then
+	if test "$with_expat" != "yes" -a "$with_expat" != ""; then
 		EXPAT_CFLAGS="-I$with_expat/include"
 		EXPAT_LIBS="-L$with_expat/lib"
 	fi
@@ -710,7 +710,7 @@ AC_DEFUN(PATH_ZLIB,
 
   ZLIB_CFLAGS=
   ZLIB_LIBS=
-  if test "$with_zlib" != "yes"; then
+  if test "$with_zlib" != "yes" -a "$with_zlib" != ""; then
     ZLIB_CFLAGS="-I$with_zlib/include"
     ZLIB_LIBS="-L$with_zlib/lib"
   fi
diff --git a/acinclude-2.5.m4 b/acinclude-2.5.m4
index 2b9bc0e98..761602d46 100644
--- a/acinclude-2.5.m4
+++ b/acinclude-2.5.m4
@@ -675,7 +675,7 @@ AC_DEFUN(PATH_EXPAT,
 
   EXPAT_CFLAGS=
   EXPAT_LIBS=
-	if test "$with_expat" != "yes"; then
+	if test "$with_expat" != "yes" -a "$with_expat" != ""; then
 		EXPAT_CFLAGS="-I$with_expat/include"
 		EXPAT_LIBS="-L$with_expat/lib"
 	fi
@@ -710,7 +710,7 @@ AC_DEFUN(PATH_ZLIB,
 
   ZLIB_CFLAGS=
   ZLIB_LIBS=
-  if test "$with_zlib" != "yes"; then
+  if test "$with_zlib" != "yes" -a "$with_zlib" != ""; then
     ZLIB_CFLAGS="-I$with_zlib/include"
     ZLIB_LIBS="-L$with_zlib/lib"
   fi
diff --git a/configure.in b/configure.in
index 5eb6d79f8..0852c5fac 100644
--- a/configure.in
+++ b/configure.in
@@ -26,7 +26,7 @@ dnl Check for headers
 AC_HEADER_STDC()
 
 CFLAGS="-Wall -Wno-sign-compare -Wno-comment -I../src @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@ @MATROSKA_CFLAGS@ @EBML_CFLAGS@"
-CXXFLAGS="-Wall -Wno-sign-compare -Wno-comment -I../avilib -I.. @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@ @MATROSKA_CFLAGS@ @EBML_CFLAGS@ @WXWINDOWS_CFLAGS@ @EXPAT_CFLAGS@"
+CXXFLAGS="-Wall -Wno-sign-compare -Wno-comment -I../avilib -I.. @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@ @MATROSKA_CFLAGS@ @EBML_CFLAGS@ @WXWINDOWS_CFLAGS@ @EXPAT_CFLAGS@ @ZLIB_CFLAGS@"
 LDFLAGS=-L../avilib
 
 AC_OUTPUT(Makefile avilib/Makefile src/Makefile doc/Makefile)
diff --git a/src/Makefile.am b/src/Makefile.am
index a61d69197..348de06d9 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -65,7 +65,7 @@ base64tool_SOURCES = base64tool.cpp \
 
 mkvmerge_LDADD = @AVILIB_LIBS@ @PROFILING_LIBS@ \
 		@MATROSKA_LIBS@ @EBML_LIBS@ @VORBIS_LIBS@ @OGG_LIBS@ \
-		@ICONV_LIBS@ @MINGW_LIBS@ @EXPAT_LIBS@ -lexpat
+		@ICONV_LIBS@ @MINGW_LIBS@ @EXPAT_LIBS@ @ZLIB_LIBS@
 
 mkvinfo_LDADD = @PROFILING_LIBS@ @MATROSKA_LIBS@ @EBML_LIBS@ @ICONV_LIBS@ \
 		@WXWINDOWS_LIBS@ @MINGW_LIBS@