diff --git a/curl-7.19.7-ares-ipv6.patch b/curl-7.19.7-ares-ipv6.patch
deleted file mode 100644
index 960e8c7..0000000
--- a/curl-7.19.7-ares-ipv6.patch
+++ /dev/null
@@ -1,16 +0,0 @@
- lib/hostares.c |    2 +-
- 1 files changed, 1 insertions(+), 1 deletions(-)
-
-diff --git a/lib/hostares.c b/lib/hostares.c
-index 01b2142..ceda98e 100644
---- a/lib/hostares.c
-+++ b/lib/hostares.c
-@@ -380,7 +380,7 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
- 
-   switch(data->set.ip_version) {
-   default:
--#if ARES_VERSION >= 0x010601
-+#if 0
-     family = PF_UNSPEC; /* supported by c-ares since 1.6.1, so for older
-                            c-ares versions this just falls through and defaults
-                            to PF_INET */
diff --git a/curl-7.20.1-threaded-dns.patch b/curl-7.20.1-threaded-dns.patch
new file mode 100644
index 0000000..b492f69
--- /dev/null
+++ b/curl-7.20.1-threaded-dns.patch
@@ -0,0 +1,25 @@
+ configure.ac |   11 +++++++++++
+ 1 files changed, 11 insertions(+), 0 deletions(-)
+
+diff --git a/configure.ac b/configure.ac
+index 39cc418..7e31459 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -2285,6 +2285,17 @@ AM_CONDITIONAL(USE_MANUAL, test x"$USE_MANUAL" = x1)
+ CURL_CHECK_LIB_ARES
+ AM_CONDITIONAL(USE_EMBEDDED_ARES, test x$embedded_ares = xyes)
+ 
++AC_CHECK_HEADER(pthread.h,
++  [ AC_DEFINE(HAVE_PTHREAD_H, 1, [if you have <pthread.h>])
++    save_CFLAGS="$CFLAGS"
++    CFLAGS="$CFLAGS -pthread"
++    AC_CHECK_LIB(pthread, pthread_create,
++      [ AC_MSG_NOTICE([using POSIX threaded DNS lookup])
++        AC_DEFINE(USE_THREADS_POSIX, 1, [if you want POSIX threaded DNS lookup])
++      ],
++      [ CFLAGS="$save_CFLAGS"])
++  ])
++
+ dnl ************************************************************
+ dnl disable verbose text strings
+ dnl
diff --git a/curl.spec b/curl.spec
index 2f492c9..b6d2051 100644
--- a/curl.spec
+++ b/curl.spec
@@ -1,7 +1,7 @@
 Summary: A utility for getting files from remote servers (FTP, HTTP, and others)
 Name: curl
 Version: 7.20.1
-Release: 1%{?dist}
+Release: 2%{?dist}
 License: MIT
 Group: Applications/Internet
 Source: http://curl.haxx.se/download/%{name}-%{version}.tar.lzma
@@ -24,10 +24,8 @@ Patch104: curl-7.19.7-s390-sleep.patch
 # use localhost6 instead of ip6-localhost in the curl test-suite
 Patch105: curl-7.19.7-localhost6.patch
 
-# rebuild of cURL against newer c-ares-devel has caused a regression (#548269)
-# this patch reverts back the old behavior of curl-7.19.7-4.fc13
-# NOTE: this is a temporary workaround only
-Patch106: curl-7.19.7-ares-ipv6.patch
+# experimentally enabled threaded DNS lookup
+Patch106: curl-7.20.1-threaded-dns.patch
 
 # exclude test1112 from the test suite (#565305)
 Patch107: curl-7.20.0-disable-test1112.patch
@@ -36,7 +34,6 @@ Provides: webclient
 URL: http://curl.haxx.se/
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 BuildRequires: automake
-BuildRequires: c-ares-devel
 BuildRequires: groff
 BuildRequires: krb5-devel
 BuildRequires: libidn-devel
@@ -48,11 +45,10 @@ BuildRequires: openssh-server
 BuildRequires: pkgconfig
 BuildRequires: stunnel
 
-# valgrind temporarily disabled (#574889)
-# # valgrind is not available on s390(x)
-# %ifnarch s390 s390x
-# BuildRequires: valgrind
-# %endif
+# valgrind is not available on s390(x)
+%ifnarch s390 s390x
+BuildRequires: valgrind
+%endif
 
 BuildRequires: zlib-devel
 Requires: libcurl = %{version}-%{release}
@@ -104,10 +100,7 @@ done
 %patch102 -p1
 %patch103 -p1
 %patch104 -p1
-
-# temporarily disabled (clash with patch #106)
-#%patch105 -p1
-
+%patch105 -p1
 %patch106 -p1
 
 # exclude test1112 from the test suite (#565305)
@@ -121,7 +114,6 @@ sed -i s/899\\\([0-9]\\\)/%{?__isa_bits}9\\1/ tests/data/test*
 
 %build
 %configure --disable-static \
-    --enable-ares \
     --enable-ipv6 \
     --enable-ldaps \
     --enable-manual \
@@ -142,7 +134,8 @@ sed -i \
 make %{?_smp_mflags}
 
 %check
-export LD_LIBRARY_PATH=$RPM_BUILD_ROOT%{_libdir}
+LD_LIBRARY_PATH=$RPM_BUILD_ROOT%{_libdir}
+export LD_LIBRARY_PATH
 
 # uncomment to use the non-stripped library in tests
 # LD_PRELOAD=`find -name \*.so`
@@ -210,6 +203,9 @@ rm -rf $RPM_BUILD_ROOT
 %{_datadir}/aclocal/libcurl.m4
 
 %changelog
+* Tue Apr 20 2010 Kamil Dudka <kdudka@redhat.com> 7.20.1-2
+- experimentally enabled threaded DNS lookup
+
 * Mon Apr 19 2010 Kamil Dudka <kdudka@redhat.com> 7.20.1-1
 - new upstream release