diff --git a/config.m4 b/config.m4
old mode 100644
new mode 100755
index e762900..ac18332
--- a/config.m4
+++ b/config.m4
@@ -1,33 +1,48 @@
 dnl $Id: config.m4 321796 2012-01-05 17:23:48Z laruence $
 PHP_ARG_WITH(lua, for lua support,
 [  --with-lua=[DIR]    Include php lua support])
+PHP_ARG_WITH(lua-version, to specify a custom lua version, [  --with-lua-version=[VERSION]]   Use the specified lua version.)
 
 if test "$PHP_LUA" != "no"; then
   if test -r $PHP_LUA/include/lua.h; then
-    LUA_DIR=$PHP_LUA
+    LUA_INCLUDE_DIR=$PHP_LUA/include
   else
     AC_MSG_CHECKING(for lua in default path)
     for i in /usr/local /usr; do
       if test -r $i/include/lua/lua.h; then
-        LUA_DIR=$i
+        LUA_INCLUDE_DIR=$i/include/lua
         AC_MSG_RESULT(found in $i)
         break
       fi
+
+      if test "$PHP_LUA_VERSION" != "yes"; then
+        if test -r $i/include/lua$PHP_LUA_VERSION/lua.h; then
+          LUA_INCLUDE_DIR=$i/include/lua$PHP_LUA_VERSION
+          AC_MSG_RESULT(found in a version-specific subdirectory of $i)
+          break
+        fi
+      fi
     done
   fi
 
-  if test -z "$LUA_DIR"; then
+  if test -z "$LUA_INCLUDE_DIR"; then
     AC_MSG_RESULT(not found)
     AC_MSG_ERROR(Please reinstall the lua distribution - lua.h should be in <lua-dir>/include/)
   fi
 
-  LUA_LIB_NAME=liblua
+  if test "$PHP_LUA_VERSION" != "yes" -a "$PHP_LUA_VERSION" != "no"; then
+    LUA_LIB_SUFFIX=lua$PHP_LUA_VERSION
+  else
+    LUA_LIB_SUFFIX=lua
+  fi
+
+  LUA_LIB_NAME=lib$LUA_LIB_SUFFIX
 
   if test -r $PHP_LUA/$PHP_LIBDIR/${LUA_LIB_NAME}.${SHLIB_SUFFIX_NAME} -o -r $PHP_LUA/$PHP_LIBDIR/${LUA_LIB_NAME}.a; then
     LUA_LIB_DIR=$PHP_LUA/$PHP_LIBDIR
   else
     AC_MSG_CHECKING(for lua library in default path)
-    for i in /usr/$PHP_LIBDIR /usr/lib /usr/lib64; do
+    for i in /usr/$PHP_LIBDIR /usr/lib /usr/lib64 /usr/lib/x86_64-linux-gnu; do
       if test -r $i/${LUA_LIB_NAME}.${SHLIB_SUFFIX_NAME} -o -r $i/${LUA_LIB_NAME}.a; then
         LUA_LIB_DIR=$i
         AC_MSG_RESULT(found in $i)
@@ -41,8 +56,8 @@ if test "$PHP_LUA" != "no"; then
     AC_MSG_ERROR(Please reinstall the lua distribution - lua library should be in <lua-dir>/lib/)
   fi
 
-  PHP_ADD_INCLUDE($LUA_DIR/include)
-  PHP_ADD_LIBRARY_WITH_PATH(lua, $LUA_LIB_DIR, LUA_SHARED_LIBADD)
+  PHP_ADD_INCLUDE($LUA_INCLUDE_DIR)
+  PHP_ADD_LIBRARY_WITH_PATH($LUA_LIB_SUFFIX, $LUA_LIB_DIR, LUA_SHARED_LIBADD) 
   PHP_SUBST(LUA_SHARED_LIBADD)
   PHP_NEW_EXTENSION(lua, lua.c lua_closure.c, $ext_shared)
 fi