diff --git a/Makefile.am b/Makefile.am
index 55088956df..c6a44a130c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -518,8 +518,7 @@ text2pcap_CFLAGS = $(GENERATED_CFLAGS)
 # Libraries with which to link text2pcap.
 text2pcap_LDADD = \
 	wsutil/libwsutil.la		\
-	@GLIB_LIBS@			\
-	@ZLIB_LIBS@
+	@GLIB_LIBS@
 
 mergecap_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -527,8 +526,7 @@ mergecap_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 mergecap_LDADD = \
 	wiretap/libwiretap.la		\
 	wsutil/libwsutil.la		\
-	@GLIB_LIBS@			\
-	@ZLIB_LIBS@
+	@GLIB_LIBS@
 
 capinfos_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -537,8 +535,7 @@ capinfos_LDADD = \
 	wiretap/libwiretap.la		\
 	wsutil/libwsutil.la		\
 	@GLIB_LIBS@			\
-	@LIBGCRYPT_LIBS@		\
-	@ZLIB_LIBS@
+	@LIBGCRYPT_LIBS@
 
 captype_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -546,8 +543,7 @@ captype_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 captype_LDADD = \
 	wiretap/libwiretap.la		\
 	wsutil/libwsutil.la		\
-	@GLIB_LIBS@			\
-	@ZLIB_LIBS@
+	@GLIB_LIBS@
 
 editcap_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -555,8 +551,7 @@ editcap_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 editcap_LDADD = \
 	wiretap/libwiretap.la		\
 	wsutil/libwsutil.la		\
-	@GLIB_LIBS@			\
-	@ZLIB_LIBS@
+	@GLIB_LIBS@
 
 reordercap_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -564,8 +559,7 @@ reordercap_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 reordercap_LDADD = \
 	wiretap/libwiretap.la		\
 	wsutil/libwsutil.la		\
-	@GLIB_LIBS@			\
-	@ZLIB_LIBS@
+	@GLIB_LIBS@
 
 randpkt_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -579,8 +573,7 @@ randpkt_LDADD = \
 	@SOCKET_LIBS@			\
 	@NSL_LIBS@			\
 	@C_ARES_LIBS@			\
-	@ADNS_LIBS@			\
-	@ZLIB_LIBS@
+	@ADNS_LIBS@
 
 dftest_CPPFLAGS = $(AM_CPPFLAGS) $(GLIB_CFLAGS)
 
@@ -637,8 +630,7 @@ dumpcap_LDADD = \
 	@SYSTEMCONFIGURATION_FRAMEWORKS@	\
 	@COREFOUNDATION_FRAMEWORKS@	\
 	@LIBCAP_LIBS@			\
-	@LIBNL_LIBS@			\
-	@ZLIB_LIBS@
+	@LIBNL_LIBS@
 
 #
 # Build the version string
diff --git a/acinclude.m4 b/acinclude.m4
index b467ef75bf..b432d4cea2 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -593,45 +593,31 @@ AC_DEFUN([AC_WIRESHARK_PCAP_REMOTE_CHECK],
 AC_DEFUN([AC_WIRESHARK_ZLIB_CHECK],
 [
 	AC_WIRESHARK_PUSH_FLAGS
-	ac_ws_saved_LIBS="$LIBS"
 
-	if test "x$zlib_dir" = "x"
+	if test "x$zlib_dir" != "x"
 	then
-	  PKG_WIRESHARK_CHECK_SYSTEM_MODULES(ZLIB, [zlib], [zlib_found=yes], [zlib_found=no])
-	fi
-
-	if test x"$zlib_found" != xyes; then
-	  if test "x$zlib_dir" != "x"; then
-	    #
-	    # The user specified a directory in which zlib resides,
-	    # so add the "include" subdirectory of that directory to
-	    # the include file search path and the "lib" subdirectory
-	    # of that directory to the library search path.
-	    #
-	    ZLIB_CFLAGS="-I$zlib_dir/include"
-	    AC_WIRESHARK_ADD_DASH_L(ZLIB_LIBS, [$zlib_dir/lib])
-	  fi
-	  AX_APPEND_FLAG(-lz, ZLIB_LIBS)
+	  #
+	  # The user specified a directory in which zlib resides,
+	  # so add the "include" subdirectory of that directory to
+	  # the include file search path and the "lib" subdirectory
+	  # of that directory to the library search path.
+	  #
+	  # XXX - if there's also a zlib in a directory that's
+	  # already in CPPFLAGS or LDFLAGS, this won't make us find
+	  # the version in the specified directory, as the compiler
+	  # and/or linker will search that other directory before it
+	  # searches the specified directory.
+	  #
+	  CPPFLAGS="$CPPFLAGS -I$zlib_dir/include"
+	  AC_WIRESHARK_ADD_DASH_L(LDFLAGS, $zlib_dir/lib)
 	fi
 
 	#
-	# Make sure we have "zlib.h".
+	# Make sure we have "zlib.h".  If we don't, it means we probably
+	# don't have zlib, so don't use it.
 	#
-	CPPFLAGS="$ZLIB_CFLAGS $CPPFLAGS"
-	AC_CHECK_HEADERS(zlib.h,
+	AC_CHECK_HEADER(zlib.h,,
 	  [
-	    #
-	    # We link with zlib to support uncompression of
-	    # gzipped network traffic, e.g. in an HTTP request
-	    # or response body.
-	    #
-	    have_zlib=yes
-	  ],
-	  [
-	    have_zlib=no
-	    ZLIB_CFLAGS=""
-	    ZLIB_LIBS=""
-
 	    if test "x$zlib_dir" != "x"
 	    then
 	      #
@@ -655,24 +641,58 @@ AC_DEFUN([AC_WIRESHARK_ZLIB_CHECK],
 		# We couldn't find the header file; don't use the
 		# library, as it's probably not present.
 		#
-		AC_MSG_NOTICE(zlib.h not found - disabling gzip compression and decompression)
+		want_zlib=no
 	      fi
 	    fi
 	  ])
 
-	if test "x$have_zlib" != "xno"
+	if test "x$want_zlib" != "xno"
 	then
+		#
+		# Well, we at least have the zlib header file.
+		# We link with zlib to support uncompression of
+		# gzipped network traffic, e.g. in an HTTP request
+		# or response body.
+		#
+		if test "x$zlib_dir" != "x"
+		then
+		  WS_CPPFLAGS="$WS_CPPFLAGS -I$zlib_dir/include"
+		  AC_WIRESHARK_ADD_DASH_L(WS_LDFLAGS, $zlib_dir/lib)
+		fi
+		LIBS="$LIBS -lz"
+		AC_DEFINE(HAVE_LIBZ, 1, [Define to use libz library])
 		#
 		# Check for "inflatePrime()" in zlib, which we need
 		# in order to read compressed capture files.
 		#
-		LIBS="$ZLIB_LIBS $LIBS"
-		AC_CHECK_FUNCS(inflatePrime,[],
-		  [AC_MSG_NOTICE(inflatePrime not found - disabling gzipped capture file support)])
+		AC_CHECK_FUNCS(inflatePrime)
+
+		if test "x$ac_cv_func_inflatePrime" = "xyes" ; then
+			#
+			# Now check for "inflatePrime()" in zlib when
+			# linking with the linker flags for GTK+
+			# applications; people often grab XFree86 source
+			# and build and install it on their systems,
+			# and they appear sometimes to misconfigure
+			# XFree86 so that, even on systems with zlib,
+			# it assumes there is no zlib, so the XFree86
+			# build process builds and installs its
+			# own zlib in the X11 library directory.
+			#
+			# The zlib in at least some versions of XFree86
+			# is an older version that may lack "inflatePrime()",
+			# and that's the zlib with which Wireshark gets
+			# linked, so the build of Wireshark fails.
+			#
+			AC_MSG_CHECKING([for inflatePrime missing when linking with X11])
+			AC_TRY_LINK_FUNC(inflatePrime, AC_MSG_RESULT(no),
+			  [
+			    AC_MSG_RESULT(yes)
+			    AC_MSG_ERROR(old zlib found when linking with X11 - get rid of old zlib.)
+			  ])
+		fi
 	fi
-	AC_SUBST(ZLIB_CFLAGS)
-	AC_SUBST(ZLIB_LIBS)
-	LIBS="$ac_ws_saved_LIBS"
+
 	AC_WIRESHARK_POP_FLAGS
 ])
 
diff --git a/configure.ac b/configure.ac
index 9e87f9b68e..c917542472 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2424,11 +2424,8 @@ else
     AC_WIRESHARK_PCAP_REMOTE_CHECK
 fi
 
-dnl
 dnl zlib check
-dnl
 AC_MSG_CHECKING(whether to use zlib for gzip compression and decompression)
-have_zlib=no
 
 AC_ARG_WITH(zlib,
   AC_HELP_STRING([--with-zlib@<:@=DIR@:>@],
@@ -2445,11 +2442,24 @@ AC_ARG_WITH(zlib,
 		zlib_dir="$withval"
 	fi
 ],[
-	want_zlib="if available"
+	#
+	# Use zlib if it's present, otherwise don't.
+	#
+	want_zlib=ifavailable
+	zlib_dir=
 ])
-AC_MSG_RESULT([$want_zlib])
-if test "x$want_zlib" != "xno" ; then
+if test "x$want_zlib" = "xno" ; then
+	AC_MSG_RESULT(no)
+else
+	AC_MSG_RESULT(yes)
 	AC_WIRESHARK_ZLIB_CHECK
+	if test "x$want_zlib" = "xno" ; then
+		AC_MSG_RESULT(zlib not found - disabling gzip compression and decompression)
+	else
+		if test "x$ac_cv_func_inflatePrime" = "xno" ; then
+			AC_MSG_RESULT(inflatePrime not found in zlib - disabling gzipped capture file support)
+		fi
+	fi
 fi
 
 dnl Lua check
@@ -3360,7 +3370,7 @@ else
 	dumpcap_group_message="$DUMPCAP_GROUP"
 fi
 
-if test "x$have_zlib" = "xno" ; then
+if test "x$want_zlib" = "xno" ; then
 	zlib_message="no"
 else
 	zlib_message="yes"
diff --git a/epan/Makefile.am b/epan/Makefile.am
index 9c79ba5468..2daae9e6e4 100644
--- a/epan/Makefile.am
+++ b/epan/Makefile.am
@@ -43,7 +43,7 @@ ACLOCAL_AMFLAGS = `../aclocal-flags`
 AM_CPPFLAGS = $(INCLUDEDIRS) -I$(builddir)/wslua $(WS_CPPFLAGS) \
 	$(GLIB_CFLAGS) $(LUA_CFLAGS) $(LIBGNUTLS_CFLAGS) \
 	$(LIBGCRYPT_CFLAGS) $(LIBSMI_CFLAGS) $(LIBGEOIP_CFLAGS) \
-	$(KRB5_CFLAGS) $(ZLIB_CFLAGS)
+	$(KRB5_CFLAGS)
 
 noinst_LTLIBRARIES = libwireshark_generated.la libwireshark_asmopt.la
 lib_LTLIBRARIES = libwireshark.la
@@ -146,7 +146,6 @@ libwireshark_la_LIBADD = \
 	@LIBSMI_LDFLAGS@	\
 	@GEOIP_LIBS@		\
 	@GLIB_LIBS@		\
-	$(ZLIB_LIBS)		\
 	-lm
 
 libwireshark_la_DEPENDENCIES = \
@@ -168,17 +167,17 @@ EXTRA_PROGRAMS = reassemble_test tvbtest oids_test
 reassemble_test_LDADD = \
 	libwireshark.la \
 	$(GLIB_LIBS) \
-	$(ZLIB_LIBS)
+	-lz
 
 tvbtest_LDADD = \
 	libwireshark.la \
 	$(GLIB_LIBS) \
-	$(ZLIB_LIBS)
+	-lz
 
 oids_test_LDADD = \
 	libwireshark.la \
 	$(GLIB_LIBS) \
-	$(ZLIB_LIBS)
+	-lz
 
 exntest: exntest.o except.o
 	$(LINK) $^ $(GLIB_LIBS)
diff --git a/epan/dissectors/Makefile.am b/epan/dissectors/Makefile.am
index 699bdef891..85673f047e 100644
--- a/epan/dissectors/Makefile.am
+++ b/epan/dissectors/Makefile.am
@@ -22,8 +22,7 @@ include Makefile.common
 include $(top_srcdir)/Makefile.am.inc
 
 AM_CPPFLAGS = $(INCLUDEDIRS) -I$(top_srcdir)/epan $(WS_CPPFLAGS) \
-	$(GLIB_CFLAGS) $(LIBGNUTLS_CFLAGS) $(LIBGCRYPT_CFLAGS) \
-	$(ZLIB_CFLAGS)
+	$(GLIB_CFLAGS) $(LIBGNUTLS_CFLAGS) $(LIBGCRYPT_CFLAGS)
 
 noinst_LTLIBRARIES = libdirtydissectors.la libfiledissectors.la libdissectors.la
 
diff --git a/epan/wslua/Makefile.am b/epan/wslua/Makefile.am
index 23a267898a..48b20925c1 100644
--- a/epan/wslua/Makefile.am
+++ b/epan/wslua/Makefile.am
@@ -22,7 +22,7 @@
 include $(top_srcdir)/Makefile.am.inc
 
 AM_CPPFLAGS = $(INCLUDEDIRS) $(WS_CPPFLAGS) $(LUA_CFLAGS) \
-	$(GLIB_CFLAGS) $(ZLIB_CFLAGS)
+	$(GLIB_CFLAGS)
 
 noinst_LTLIBRARIES = libwslua.la
 
diff --git a/wiretap/Makefile.am b/wiretap/Makefile.am
index 3be75a7545..d716817767 100644
--- a/wiretap/Makefile.am
+++ b/wiretap/Makefile.am
@@ -24,8 +24,7 @@ include $(top_srcdir)/Makefile.am.inc
 
 ACLOCAL_AMFLAGS = `../aclocal-flags`
 
-AM_CPPFLAGS = $(INCLUDEDIRS) $(WS_CPPFLAGS) -DWS_BUILD_DLL $(GLIB_CFLAGS) \
-	$(ZLIB_CFLAGS)
+AM_CPPFLAGS = $(INCLUDEDIRS) $(WS_CPPFLAGS) -DWS_BUILD_DLL $(GLIB_CFLAGS)
 
 noinst_LTLIBRARIES = libwiretap_generated.la
 lib_LTLIBRARIES = libwiretap.la
@@ -64,11 +63,7 @@ EXTRA_DIST = \
 	$(GENERATOR_FILES) 	\
 	$(GENERATED_FILES)
 
-libwiretap_la_LIBADD = \
-	libwiretap_generated.la		\
-	${top_builddir}/wsutil/libwsutil.la \
-	$(GLIB_LIBS)			\
-	$(ZLIB_LIBS)
+libwiretap_la_LIBADD = libwiretap_generated.la ${top_builddir}/wsutil/libwsutil.la $(GLIB_LIBS)
 
 libwiretap_la_DEPENDENCIES = libwiretap_generated.la ${top_builddir}/wsutil/libwsutil.la