diff --git a/m4/ChangeLog b/m4/ChangeLog
index 471b0b552..54c601646 100644
--- a/m4/ChangeLog
+++ b/m4/ChangeLog
@@ -1,3 +1,7 @@
+2007-07-27  David Shaw  <dshaw@jabberwocky.com>
+
+	* ldap.m4: If we don't find ldap or winldap, try for mozldap.
+
 2007-01-16  David Shaw  <dshaw@jabberwocky.com>
 
 	* libcurl.m4: Check for curl_easy_escape() and
diff --git a/m4/ldap.m4 b/m4/ldap.m4
index 95249ac3e..29ac078ee 100644
--- a/m4/ldap.m4
+++ b/m4/ldap.m4
@@ -1,5 +1,5 @@
 dnl Check for LDAP
-dnl Copyright (C) 2005 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2007 Free Software Foundation, Inc.
 dnl
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
@@ -33,10 +33,11 @@ if test x$_ldap_with != xno ; then
   CPPFLAGS="${LDAP_CPPFLAGS} ${CPPFLAGS}"
   _ldap_save_ldflags=$LDFLAGS
   LDFLAGS="${LDAP_LDFLAGS} ${LDFLAGS}"
+  _ldap_save_libs=$LIBS
 
   for MY_LDAPLIBS in ${LDAPLIBS+"$LDAPLIBS"} "-lldap" "-lldap -llber" "-lldap -llber -lresolv" "-lwldap32"; do
-    _ldap_save_libs=$LIBS
-    LIBS="$MY_LDAPLIBS $1 $LIBS"
+
+    LIBS="$MY_LDAPLIBS $1 $_ldap_save_libs"
 
     AC_MSG_CHECKING([whether LDAP via \"$MY_LDAPLIBS\" is present and sane])
     AC_TRY_LINK([
@@ -59,39 +60,62 @@ if test x$_ldap_with != xno ; then
     fi
 
     if test "$gnupg_cv_func_ldaplber_init" = yes ; then
-       AC_DEFINE(NEED_LBER_H,1,[Define if the LDAP library requires including lber.h before ldap.h])
+       AC_DEFINE(NEED_LBER_H,1,
+          [Define if the LDAP library requires including lber.h before ldap.h])
     fi
 
     if test "$gnupg_cv_func_ldap_init" = yes || \
         test "$gnupg_cv_func_ldaplber_init" = yes ; then
        LDAPLIBS="$LDAP_LDFLAGS $MY_LDAPLIBS"
        GPGKEYS_LDAP="gpgkeys_ldap$EXEEXT"
-
-       AC_CHECK_FUNCS(ldap_get_option ldap_set_option ldap_start_tls_s)
-
-       if test "$ac_cv_func_ldap_get_option" != yes ; then
-          AC_MSG_CHECKING([whether LDAP supports ld_errno])
-	  AC_TRY_LINK([#include <ldap.h>],[LDAP *ldap; ldap->ld_errno;],
-	     [gnupg_cv_func_ldap_ld_errno=yes],
-	     [gnupg_cv_func_ldap_ld_errno=no])
-          AC_MSG_RESULT([$gnupg_cv_func_ldap_ld_errno])
-
-	  if test "$gnupg_cv_func_ldap_ld_errno" = yes ; then
-	     AC_DEFINE(HAVE_LDAP_LD_ERRNO,1,[Define if the LDAP library supports ld_errno])
-          fi
-       fi
+       break
     fi
-
-    LIBS=$_ldap_save_libs
-
-    if test "$GPGKEYS_LDAP" != "" ; then break; fi
   done
 
+  if test "$GPGKEYS_LDAP" = "" ; then
+     # It didn't work, so try for mozldap.  We only do this via
+     # pkg-config due to a really impressive dependency list.
+     AC_PATH_PROG([_pkg_config],[pkg-config])
+     if test x$_pkg_config != x ; then
+        AC_MSG_CHECKING([for mozldap])
+	LDAPLIBS=`$_pkg_config --libs mozldap 2>/dev/null`
+        LDAP_CPPFLAGS=`$_pkg_config --cflags mozldap 2>/dev/null`
+        if test x"$LDAPLIBS" = x && test x"$LDAP_CPPFLAGS" = x; then
+           AC_MSG_RESULT([no])
+        else
+           AC_MSG_RESULT([yes])
+	   LIBS="$LDAPLIBS"
+	   GPGKEYS_LDAP="gpgkeys_ldap$EXEEXT"
+	   CPPFLAGS="${LDAP_CPPFLAGS} ${CPPFLAGS}"
+	   AC_CHECK_HEADERS([ldap_ssl.h],,,[#include <ldap.h>])
+        fi
+     fi
+  fi
+
+  if test "$GPGKEYS_LDAP" != "" ; then
+     # Whichever library we ended up with, check for some features...
+     AC_CHECK_FUNCS(ldap_get_option ldap_set_option ldap_start_tls_s)
+
+     if test "$ac_cv_func_ldap_get_option" != yes ; then
+        AC_MSG_CHECKING([whether LDAP supports ld_errno])
+        AC_TRY_LINK([#include <ldap.h>],[LDAP *ldap; ldap->ld_errno;],
+           [gnupg_cv_func_ldap_ld_errno=yes],
+           [gnupg_cv_func_ldap_ld_errno=no])
+        AC_MSG_RESULT([$gnupg_cv_func_ldap_ld_errno])
+
+        if test "$gnupg_cv_func_ldap_ld_errno" = yes ; then
+	   AC_DEFINE(HAVE_LDAP_LD_ERRNO,1,
+                     [Define if the LDAP library supports ld_errno])
+        fi
+     fi
+  fi
+
+  LIBS=$_ldap_save_libs
+  CPPFLAGS=$_ldap_save_cppflags
+  LDFLAGS=$_ldap_save_ldflags
+
   AC_SUBST(GPGKEYS_LDAP)
   AC_SUBST(LDAPLIBS)
   AC_SUBST(LDAP_CPPFLAGS)
-
-  CPPFLAGS=$_ldap_save_cppflags
-  LDFLAGS=$_ldap_save_ldflags
 fi
 ])dnl