diff --git a/ext/curl/interface.c b/ext/curl/interface.c
index 15e6133fe84..173502877e6 100644
--- a/ext/curl/interface.c
+++ b/ext/curl/interface.c
@@ -157,7 +157,7 @@ static void _php_curl_close(zend_resource *rsrc TSRMLS_DC);
 #define CAAL(s, v) add_assoc_long_ex(return_value, s, sizeof(s) - 1, (long) v);
 #define CAAD(s, v) add_assoc_double_ex(return_value, s, sizeof(s) - 1, (double) v);
 #define CAAS(s, v) add_assoc_string_ex(return_value, s, sizeof(s) - 1, (char *) (v ? v : ""));
-#define CAASTR(s, v) add_assoc_str_ex(return_value, s, sizeof(s) - 1, v? v : "");
+#define CAASTR(s, v) add_assoc_str_ex(return_value, s, sizeof(s) - 1, v ? v : STR_EMPTY_ALLOC());
 #define CAAZ(s, v) add_assoc_zval_ex(return_value, s, sizeof(s) -1 , (zval *) v);
 
 #if defined(PHP_WIN32) || defined(__GNUC__)