diff --git a/aclocal/ax_boost_base.m4 b/aclocal/ax_boost_base.m4
index 8e6ee9a..b496020 100644
--- a/aclocal/ax_boost_base.m4
+++ b/aclocal/ax_boost_base.m4
@@ -121,7 +121,7 @@
                 fi
         done
     elif test "$cross_compiling" != yes; then
-        for ac_boost_path_tmp in /usr /usr/local /opt /opt/local ; do
+        for ac_boost_path_tmp in $lt_sysroot/usr $lt_sysroot/usr/local $lt_sysroot/opt $lt_sysroot/opt/local ; do
             if test -d "$ac_boost_path_tmp/include/boost" && test -r "$ac_boost_path_tmp/include/boost"; then
                 for libsubdir in $libsubdirs ; do
                     if ls "$ac_boost_path_tmp/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
@@ -185,7 +185,7 @@
             fi
         else
             if test "$cross_compiling" != yes; then
-                for ac_boost_path in /usr /usr/local /opt /opt/local ; do
+                for ac_boost_path in $lt_sysroot/usr $lt_sysroot/usr/local $lt_sysroot/opt $lt_sysroot/opt/local ; do
                     if test -d "$ac_boost_path" && test -r "$ac_boost_path"; then
                         for i in `ls -d $ac_boost_path/include/boost-* 2>/dev/null`; do
                             _version_tmp=`echo $i | sed "s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
diff --git a/aclocal/ax_lib_event.m4 b/aclocal/ax_lib_event.m4
index 7d2f98a..cf6c4c2 100644
--- a/aclocal/ax_lib_event.m4
+++ b/aclocal/ax_lib_event.m4
@@ -165,7 +165,7 @@
             if test -n "$ax_libevent_path"; then
               AX_LIB_EVENT_DO_CHECK
             else
-              for ax_libevent_path in "" /usr /usr/local /opt /opt/local /opt/libevent "$LIBEVENT_ROOT" ; do
+              for ax_libevent_path in "" $lt_sysroot/usr $lt_sysroot/usr/local $lt_sysroot/opt $lt_sysroot/opt/local $lt_sysroot/opt/libevent "$LIBEVENT_ROOT" ; do
                 AX_LIB_EVENT_DO_CHECK
                 if test "$success" = "yes"; then
                   break;