diff --git a/libs/Smarty_Compiler.class.php b/libs/Smarty_Compiler.class.php
index 296e853f..355049e3 100644
--- a/libs/Smarty_Compiler.class.php
+++ b/libs/Smarty_Compiler.class.php
@@ -927,8 +927,8 @@ class Smarty_Compiler extends Smarty {
             $this->_syntax_error("missing 'file' attribute in include_php tag", E_USER_ERROR, __FILE__, __LINE__);
         }
 
-        $assign_var = $this->_dequote($attrs['assign']);
-        $once_var = ( $attrs['once'] == 'false' ) ? 'false' : 'true';
+        $assign_var = (empty($attrs['assign'])) ? '' : $this->_dequote($attrs['assign']);
+        $once_var = (empty($attrs['once']) || $attrs['once']=='false') ? 'false' : 'true';
 
         foreach($attrs as $arg_name => $arg_value) {
             if($arg_name != 'file' AND $arg_name != 'once' AND $arg_name != 'assign') {