diff --git a/Makefile.in b/Makefile.in
index 8a175766..0eaa3906 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -39,10 +39,11 @@ DIST_COMMON = $(am__configure_deps) $(srcdir)/Makefile.am \
 	$(top_srcdir)/configure COPYING INSTALL config.guess \
 	config.sub depcomp install-sh ltmain.sh missing
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/m4/libtool.m4 \
-	$(top_srcdir)/m4/ltoptions.m4 $(top_srcdir)/m4/ltsugar.m4 \
-	$(top_srcdir)/m4/ltversion.m4 $(top_srcdir)/m4/lt~obsolete.m4 \
-	$(top_srcdir)/libev/libev.m4 $(top_srcdir)/configure.ac
+am__aclocal_m4_deps = $(top_srcdir)/m4/acx_pthread.m4 \
+	$(top_srcdir)/m4/libtool.m4 $(top_srcdir)/m4/ltoptions.m4 \
+	$(top_srcdir)/m4/ltsugar.m4 $(top_srcdir)/m4/ltversion.m4 \
+	$(top_srcdir)/m4/lt~obsolete.m4 $(top_srcdir)/libev/libev.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \
@@ -163,6 +164,9 @@ PACKAGE_TARNAME = @PACKAGE_TARNAME@
 PACKAGE_URL = @PACKAGE_URL@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 PATH_SEPARATOR = @PATH_SEPARATOR@
+PTHREAD_CC = @PTHREAD_CC@
+PTHREAD_CFLAGS = @PTHREAD_CFLAGS@
+PTHREAD_LIBS = @PTHREAD_LIBS@
 RANLIB = @RANLIB@
 SED = @SED@
 SET_MAKE = @SET_MAKE@
@@ -176,6 +180,7 @@ abs_top_srcdir = @abs_top_srcdir@
 ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
+acx_pthread_config = @acx_pthread_config@
 am__include = @am__include@
 am__leading_dot = @am__leading_dot@
 am__quote = @am__quote@
diff --git a/aclocal.m4 b/aclocal.m4
index 2dd8f06f..92e2b12d 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -969,6 +969,7 @@ AC_SUBST([am__tar])
 AC_SUBST([am__untar])
 ]) # _AM_PROG_TAR
 
+m4_include([m4/acx_pthread.m4])
 m4_include([m4/libtool.m4])
 m4_include([m4/ltoptions.m4])
 m4_include([m4/ltsugar.m4])
diff --git a/config.h.in b/config.h.in
index bc521597..c482f709 100644
--- a/config.h.in
+++ b/config.h.in
@@ -84,6 +84,9 @@
 /* Define to 1 if you have the <port.h> header file. */
 #undef HAVE_PORT_H
 
+/* Define if you have POSIX threads libraries and header files. */
+#undef HAVE_PTHREAD
+
 /* Define to 1 if you have the `select' function. */
 #undef HAVE_SELECT
 
@@ -190,6 +193,10 @@
 /* Define to the version of this package. */
 #undef PACKAGE_VERSION
 
+/* Define to the necessary symbol if this constant uses a non-standard name on
+   your system. */
+#undef PTHREAD_CREATE_JOINABLE
+
 /* Define as the return type of signal handlers (`int' or `void'). */
 #undef RETSIGTYPE
 
diff --git a/configure b/configure
index db2f3d54..4696643f 100755
--- a/configure
+++ b/configure
@@ -615,6 +615,10 @@ ac_includes_default="\
 ac_subst_vars='am__EXEEXT_FALSE
 am__EXEEXT_TRUE
 LTLIBOBJS
+PTHREAD_CFLAGS
+PTHREAD_LIBS
+PTHREAD_CC
+acx_pthread_config
 LIBOBJS
 CPP
 OTOOL64
@@ -13048,6 +13052,365 @@ done
 
 
 
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+acx_pthread_ok=no
+
+# We used to check for pthread.h first, but this fails if pthread.h
+# requires special compiler flags (e.g. on True64 or Sequent).
+# It gets checked for in the link test anyway.
+
+# First of all, check if the user has set any of the PTHREAD_LIBS,
+# etcetera environment variables, and if threads linking works using
+# them:
+if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS" >&5
+$as_echo_n "checking for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS... " >&6; }
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_join ();
+int
+main ()
+{
+return pthread_join ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  acx_pthread_ok=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: $acx_pthread_ok" >&5
+$as_echo "$acx_pthread_ok" >&6; }
+        if test x"$acx_pthread_ok" = xno; then
+                PTHREAD_LIBS=""
+                PTHREAD_CFLAGS=""
+        fi
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+fi
+
+# We must check for the threads library under a number of different
+# names; the ordering is very important because some systems
+# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
+# libraries is broken (non-POSIX).
+
+# Create a list of thread flags to try.  Items starting with a "-" are
+# C compiler flags, and other items are library names, except for "none"
+# which indicates that we try without any flags at all, and "pthread-config"
+# which is a program returning the flags for the Pth emulation library.
+
+acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+
+# The ordering *is* (sometimes) important.  Some notes on the
+# individual items follow:
+
+# pthreads: AIX (must check this before -lpthread)
+# none: in case threads are in libc; should be tried before -Kthread and
+#       other compiler flags to prevent continual compiler warnings
+# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
+# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
+# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
+# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
+# -pthreads: Solaris/gcc
+# -mthreads: Mingw32/gcc, Lynx/gcc
+# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
+#      doesn't hurt to check since this sometimes defines pthreads too;
+#      also defines -D_REENTRANT)
+# pthread: Linux, etcetera
+# --thread-safe: KAI C++
+# pthread-config: use pthread-config program (for GNU Pth library)
+
+case "${host_cpu}-${host_os}" in
+        *solaris*)
+
+        # On Solaris (at least, for some versions), libc contains stubbed
+        # (non-functional) versions of the pthreads routines, so link-based
+        # tests will erroneously succeed.  (We need to link with -pthread or
+        # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
+        # a function called by this macro, so we could check for that, but
+        # who knows whether they'll stub that too in a future libc.)  So,
+        # we'll just look for -pthreads and -lpthread first:
+
+        acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
+        ;;
+esac
+
+if test x"$acx_pthread_ok" = xno; then
+for flag in $acx_pthread_flags; do
+
+        case $flag in
+                none)
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether pthreads work without any flags" >&5
+$as_echo_n "checking whether pthreads work without any flags... " >&6; }
+                ;;
+
+                -*)
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether pthreads work with $flag" >&5
+$as_echo_n "checking whether pthreads work with $flag... " >&6; }
+                PTHREAD_CFLAGS="$flag"
+                ;;
+
+		pthread-config)
+		# Extract the first word of "pthread-config", so it can be a program name with args.
+set dummy pthread-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_acx_pthread_config+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$acx_pthread_config"; then
+  ac_cv_prog_acx_pthread_config="$acx_pthread_config" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_acx_pthread_config="yes"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_prog_acx_pthread_config" && ac_cv_prog_acx_pthread_config="no"
+fi
+fi
+acx_pthread_config=$ac_cv_prog_acx_pthread_config
+if test -n "$acx_pthread_config"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $acx_pthread_config" >&5
+$as_echo "$acx_pthread_config" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+		if test x"$acx_pthread_config" = xno; then continue; fi
+		PTHREAD_CFLAGS="`pthread-config --cflags`"
+		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+		;;
+
+                *)
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for the pthreads library -l$flag" >&5
+$as_echo_n "checking for the pthreads library -l$flag... " >&6; }
+                PTHREAD_LIBS="-l$flag"
+                ;;
+        esac
+
+        save_LIBS="$LIBS"
+        save_CFLAGS="$CFLAGS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Check for various functions.  We must include pthread.h,
+        # since some functions may be macros.  (On the Sequent, we
+        # need a special flag -Kthread to make this header compile.)
+        # We check for pthread_join because it is in -lpthread on IRIX
+        # while pthread_create is in libc.  We check for pthread_attr_init
+        # due to DEC craziness with -lpthreads.  We check for
+        # pthread_cleanup_push because it is one of the few pthread
+        # functions on Solaris that doesn't have a non-functional libc stub.
+        # We try pthread_create on general principles.
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+int
+main ()
+{
+pthread_t th; pthread_join(th, 0);
+                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
+                     pthread_create(0,0,0,0); pthread_cleanup_pop(0);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  acx_pthread_ok=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: $acx_pthread_ok" >&5
+$as_echo "$acx_pthread_ok" >&6; }
+        if test "x$acx_pthread_ok" = xyes; then
+                break;
+        fi
+
+        PTHREAD_LIBS=""
+        PTHREAD_CFLAGS=""
+done
+fi
+
+# Various other checks:
+if test "x$acx_pthread_ok" = xyes; then
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Detect AIX lossage: threads are created detached by default
+        # and the JOINABLE attribute has a nonstandard name (UNDETACHED).
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for joinable pthread attribute" >&5
+$as_echo_n "checking for joinable pthread attribute... " >&6; }
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+int
+main ()
+{
+int attr=PTHREAD_CREATE_JOINABLE;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ok=PTHREAD_CREATE_JOINABLE
+else
+  ok=unknown
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+        if test x"$ok" = xunknown; then
+                cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+int
+main ()
+{
+int attr=PTHREAD_CREATE_UNDETACHED;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ok=PTHREAD_CREATE_UNDETACHED
+else
+  ok=unknown
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+        fi
+        if test x"$ok" != xPTHREAD_CREATE_JOINABLE; then
+
+$as_echo "#define PTHREAD_CREATE_JOINABLE \$ok" >>confdefs.h
+
+        fi
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${ok}" >&5
+$as_echo "${ok}" >&6; }
+        if test x"$ok" = xunknown; then
+                { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: we do not know how to create joinable pthreads" >&5
+$as_echo "$as_me: WARNING: we do not know how to create joinable pthreads" >&2;}
+        fi
+
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking if more special flags are required for pthreads" >&5
+$as_echo_n "checking if more special flags are required for pthreads... " >&6; }
+        flag=no
+        case "${host_cpu}-${host_os}" in
+                *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
+                *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
+        esac
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${flag}" >&5
+$as_echo "${flag}" >&6; }
+        if test "x$flag" != xno; then
+                PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
+        fi
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        # More AIX lossage: must compile with cc_r
+        # Extract the first word of "cc_r", so it can be a program name with args.
+set dummy cc_r; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_PTHREAD_CC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$PTHREAD_CC"; then
+  ac_cv_prog_PTHREAD_CC="$PTHREAD_CC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_PTHREAD_CC="cc_r"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_prog_PTHREAD_CC" && ac_cv_prog_PTHREAD_CC="${CC}"
+fi
+fi
+PTHREAD_CC=$ac_cv_prog_PTHREAD_CC
+if test -n "$PTHREAD_CC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PTHREAD_CC" >&5
+$as_echo "$PTHREAD_CC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+else
+        PTHREAD_CC="$CC"
+fi
+
+
+
+
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test x"$acx_pthread_ok" = xyes; then
+
+$as_echo "#define HAVE_PTHREAD 1" >>confdefs.h
+
+        :
+else
+        acx_pthread_ok=no
+
+fi
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
+
+
 ac_config_files="$ac_config_files Makefile libasyncns/Makefile libev/Makefile src/Makefile"
 
 cat >confcache <<\_ACEOF
diff --git a/configure.ac b/configure.ac
index ac74cf38..cae0c5d5 100755
--- a/configure.ac
+++ b/configure.ac
@@ -58,6 +58,8 @@ AC_CHECK_LIB(socket, connect)
 # Checks for library functions.
 AC_CHECK_FUNCS([malloc memset socket])
 
+ACX_PTHREAD
+
 AC_CONFIG_MACRO_DIR([m4])
 
 AC_CONFIG_FILES([Makefile
diff --git a/libasyncns/Makefile.in b/libasyncns/Makefile.in
index f9a44d37..f92b0196 100644
--- a/libasyncns/Makefile.in
+++ b/libasyncns/Makefile.in
@@ -57,10 +57,11 @@ subdir = libasyncns
 DIST_COMMON = $(include_HEADERS) $(srcdir)/Makefile.am \
 	$(srcdir)/Makefile.in
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/m4/libtool.m4 \
-	$(top_srcdir)/m4/ltoptions.m4 $(top_srcdir)/m4/ltsugar.m4 \
-	$(top_srcdir)/m4/ltversion.m4 $(top_srcdir)/m4/lt~obsolete.m4 \
-	$(top_srcdir)/libev/libev.m4 $(top_srcdir)/configure.ac
+am__aclocal_m4_deps = $(top_srcdir)/m4/acx_pthread.m4 \
+	$(top_srcdir)/m4/libtool.m4 $(top_srcdir)/m4/ltoptions.m4 \
+	$(top_srcdir)/m4/ltsugar.m4 $(top_srcdir)/m4/ltversion.m4 \
+	$(top_srcdir)/m4/lt~obsolete.m4 $(top_srcdir)/libev/libev.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 mkinstalldirs = $(install_sh) -d
@@ -96,7 +97,8 @@ am__uninstall_files_from_dir = { \
   }
 am__installdirs = "$(DESTDIR)$(libdir)" "$(DESTDIR)$(includedir)"
 LTLIBRARIES = $(lib_LTLIBRARIES)
-libasyncns_la_DEPENDENCIES =
+am__DEPENDENCIES_1 =
+libasyncns_la_DEPENDENCIES = $(am__DEPENDENCIES_1)
 am_libasyncns_la_OBJECTS = asyncns.lo
 libasyncns_la_OBJECTS = $(am_libasyncns_la_OBJECTS)
 DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir)
@@ -173,6 +175,9 @@ PACKAGE_TARNAME = @PACKAGE_TARNAME@
 PACKAGE_URL = @PACKAGE_URL@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 PATH_SEPARATOR = @PATH_SEPARATOR@
+PTHREAD_CC = @PTHREAD_CC@
+PTHREAD_CFLAGS = @PTHREAD_CFLAGS@
+PTHREAD_LIBS = @PTHREAD_LIBS@
 RANLIB = @RANLIB@
 SED = @SED@
 SET_MAKE = @SET_MAKE@
@@ -186,6 +191,7 @@ abs_top_srcdir = @abs_top_srcdir@
 ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
+acx_pthread_config = @acx_pthread_config@
 am__include = @am__include@
 am__leading_dot = @am__leading_dot@
 am__quote = @am__quote@
diff --git a/libev/Makefile.in b/libev/Makefile.in
index 60bae319..820d8cb1 100644
--- a/libev/Makefile.in
+++ b/libev/Makefile.in
@@ -40,10 +40,11 @@ DIST_COMMON = README $(include_HEADERS) $(srcdir)/Makefile.am \
 	$(srcdir)/Makefile.in config.guess config.sub depcomp \
 	install-sh ltmain.sh missing mkinstalldirs
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/m4/libtool.m4 \
-	$(top_srcdir)/m4/ltoptions.m4 $(top_srcdir)/m4/ltsugar.m4 \
-	$(top_srcdir)/m4/ltversion.m4 $(top_srcdir)/m4/lt~obsolete.m4 \
-	$(top_srcdir)/libev/libev.m4 $(top_srcdir)/configure.ac
+am__aclocal_m4_deps = $(top_srcdir)/m4/acx_pthread.m4 \
+	$(top_srcdir)/m4/libtool.m4 $(top_srcdir)/m4/ltoptions.m4 \
+	$(top_srcdir)/m4/ltsugar.m4 $(top_srcdir)/m4/ltversion.m4 \
+	$(top_srcdir)/m4/lt~obsolete.m4 $(top_srcdir)/libev/libev.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 mkinstalldirs = $(install_sh) -d
@@ -163,6 +164,9 @@ PACKAGE_TARNAME = @PACKAGE_TARNAME@
 PACKAGE_URL = @PACKAGE_URL@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 PATH_SEPARATOR = @PATH_SEPARATOR@
+PTHREAD_CC = @PTHREAD_CC@
+PTHREAD_CFLAGS = @PTHREAD_CFLAGS@
+PTHREAD_LIBS = @PTHREAD_LIBS@
 RANLIB = @RANLIB@
 SED = @SED@
 SET_MAKE = @SET_MAKE@
@@ -176,6 +180,7 @@ abs_top_srcdir = @abs_top_srcdir@
 ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
+acx_pthread_config = @acx_pthread_config@
 am__include = @am__include@
 am__leading_dot = @am__leading_dot@
 am__quote = @am__quote@
diff --git a/m4/acx_pthread.m4 b/m4/acx_pthread.m4
new file mode 100644
index 00000000..bedf51c3
--- /dev/null
+++ b/m4/acx_pthread.m4
@@ -0,0 +1,199 @@
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://www.gnu.org/software/ac-archive/htmldoc/acx_pthread.html
+dnl
+AC_DEFUN([ACX_PTHREAD], [
+AC_REQUIRE([AC_CANONICAL_HOST])
+AC_LANG_SAVE
+AC_LANG_C
+acx_pthread_ok=no
+
+# We used to check for pthread.h first, but this fails if pthread.h
+# requires special compiler flags (e.g. on True64 or Sequent).
+# It gets checked for in the link test anyway.
+
+# First of all, check if the user has set any of the PTHREAD_LIBS,
+# etcetera environment variables, and if threads linking works using
+# them:
+if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
+        AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
+        AC_MSG_RESULT($acx_pthread_ok)
+        if test x"$acx_pthread_ok" = xno; then
+                PTHREAD_LIBS=""
+                PTHREAD_CFLAGS=""
+        fi
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+fi
+
+# We must check for the threads library under a number of different
+# names; the ordering is very important because some systems
+# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
+# libraries is broken (non-POSIX).
+
+# Create a list of thread flags to try.  Items starting with a "-" are
+# C compiler flags, and other items are library names, except for "none"
+# which indicates that we try without any flags at all, and "pthread-config"
+# which is a program returning the flags for the Pth emulation library.
+
+acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+
+# The ordering *is* (sometimes) important.  Some notes on the
+# individual items follow:
+
+# pthreads: AIX (must check this before -lpthread)
+# none: in case threads are in libc; should be tried before -Kthread and
+#       other compiler flags to prevent continual compiler warnings
+# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
+# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
+# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
+# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
+# -pthreads: Solaris/gcc
+# -mthreads: Mingw32/gcc, Lynx/gcc
+# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
+#      doesn't hurt to check since this sometimes defines pthreads too;
+#      also defines -D_REENTRANT)
+# pthread: Linux, etcetera
+# --thread-safe: KAI C++
+# pthread-config: use pthread-config program (for GNU Pth library)
+
+case "${host_cpu}-${host_os}" in
+        *solaris*)
+
+        # On Solaris (at least, for some versions), libc contains stubbed
+        # (non-functional) versions of the pthreads routines, so link-based
+        # tests will erroneously succeed.  (We need to link with -pthread or
+        # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
+        # a function called by this macro, so we could check for that, but
+        # who knows whether they'll stub that too in a future libc.)  So,
+        # we'll just look for -pthreads and -lpthread first:
+
+        acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
+        ;;
+esac
+
+if test x"$acx_pthread_ok" = xno; then
+for flag in $acx_pthread_flags; do
+
+        case $flag in
+                none)
+                AC_MSG_CHECKING([whether pthreads work without any flags])
+                ;;
+
+                -*)
+                AC_MSG_CHECKING([whether pthreads work with $flag])
+                PTHREAD_CFLAGS="$flag"
+                ;;
+
+		pthread-config)
+		AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
+		if test x"$acx_pthread_config" = xno; then continue; fi
+		PTHREAD_CFLAGS="`pthread-config --cflags`"
+		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+		;;
+
+                *)
+                AC_MSG_CHECKING([for the pthreads library -l$flag])
+                PTHREAD_LIBS="-l$flag"
+                ;;
+        esac
+
+        save_LIBS="$LIBS"
+        save_CFLAGS="$CFLAGS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Check for various functions.  We must include pthread.h,
+        # since some functions may be macros.  (On the Sequent, we
+        # need a special flag -Kthread to make this header compile.)
+        # We check for pthread_join because it is in -lpthread on IRIX
+        # while pthread_create is in libc.  We check for pthread_attr_init
+        # due to DEC craziness with -lpthreads.  We check for
+        # pthread_cleanup_push because it is one of the few pthread
+        # functions on Solaris that doesn't have a non-functional libc stub.
+        # We try pthread_create on general principles.
+        AC_TRY_LINK([#include <pthread.h>],
+                    [pthread_t th; pthread_join(th, 0);
+                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
+                     pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
+                    [acx_pthread_ok=yes])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        AC_MSG_RESULT($acx_pthread_ok)
+        if test "x$acx_pthread_ok" = xyes; then
+                break;
+        fi
+
+        PTHREAD_LIBS=""
+        PTHREAD_CFLAGS=""
+done
+fi
+
+# Various other checks:
+if test "x$acx_pthread_ok" = xyes; then
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Detect AIX lossage: threads are created detached by default
+        # and the JOINABLE attribute has a nonstandard name (UNDETACHED).
+        AC_MSG_CHECKING([for joinable pthread attribute])
+        AC_TRY_LINK([#include <pthread.h>],
+                    [int attr=PTHREAD_CREATE_JOINABLE;],
+                    ok=PTHREAD_CREATE_JOINABLE, ok=unknown)
+        if test x"$ok" = xunknown; then
+                AC_TRY_LINK([#include <pthread.h>],
+                            [int attr=PTHREAD_CREATE_UNDETACHED;],
+                            ok=PTHREAD_CREATE_UNDETACHED, ok=unknown)
+        fi
+        if test x"$ok" != xPTHREAD_CREATE_JOINABLE; then
+                AC_DEFINE(PTHREAD_CREATE_JOINABLE, $ok,
+                          [Define to the necessary symbol if this constant
+                           uses a non-standard name on your system.])
+        fi
+        AC_MSG_RESULT(${ok})
+        if test x"$ok" = xunknown; then
+                AC_MSG_WARN([we do not know how to create joinable pthreads])
+        fi
+
+        AC_MSG_CHECKING([if more special flags are required for pthreads])
+        flag=no
+        case "${host_cpu}-${host_os}" in
+                *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
+                *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
+        esac
+        AC_MSG_RESULT(${flag})
+        if test "x$flag" != xno; then
+                PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
+        fi
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        # More AIX lossage: must compile with cc_r
+        AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
+else
+        PTHREAD_CC="$CC"
+fi
+
+AC_SUBST(PTHREAD_LIBS)
+AC_SUBST(PTHREAD_CFLAGS)
+AC_SUBST(PTHREAD_CC)
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test x"$acx_pthread_ok" = xyes; then
+        ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
+        :
+else
+        acx_pthread_ok=no
+        $2
+fi
+AC_LANG_RESTORE
+])dnl ACX_PTHREAD
diff --git a/src/Makefile.in b/src/Makefile.in
index 30b95aa1..eb832092 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -38,10 +38,11 @@ bin_PROGRAMS = ss-local$(EXEEXT) ss-server$(EXEEXT)
 subdir = src
 DIST_COMMON = $(srcdir)/Makefile.am $(srcdir)/Makefile.in
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
-am__aclocal_m4_deps = $(top_srcdir)/m4/libtool.m4 \
-	$(top_srcdir)/m4/ltoptions.m4 $(top_srcdir)/m4/ltsugar.m4 \
-	$(top_srcdir)/m4/ltversion.m4 $(top_srcdir)/m4/lt~obsolete.m4 \
-	$(top_srcdir)/libev/libev.m4 $(top_srcdir)/configure.ac
+am__aclocal_m4_deps = $(top_srcdir)/m4/acx_pthread.m4 \
+	$(top_srcdir)/m4/libtool.m4 $(top_srcdir)/m4/ltoptions.m4 \
+	$(top_srcdir)/m4/ltsugar.m4 $(top_srcdir)/m4/ltversion.m4 \
+	$(top_srcdir)/m4/lt~obsolete.m4 $(top_srcdir)/libev/libev.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 mkinstalldirs = $(install_sh) -d
@@ -133,6 +134,9 @@ PACKAGE_TARNAME = @PACKAGE_TARNAME@
 PACKAGE_URL = @PACKAGE_URL@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 PATH_SEPARATOR = @PATH_SEPARATOR@
+PTHREAD_CC = @PTHREAD_CC@
+PTHREAD_CFLAGS = @PTHREAD_CFLAGS@
+PTHREAD_LIBS = @PTHREAD_LIBS@
 RANLIB = @RANLIB@
 SED = @SED@
 SET_MAKE = @SET_MAKE@
@@ -146,6 +150,7 @@ abs_top_srcdir = @abs_top_srcdir@
 ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
+acx_pthread_config = @acx_pthread_config@
 am__include = @am__include@
 am__leading_dot = @am__leading_dot@
 am__quote = @am__quote@