diff --git a/ext/interbase/php_ibase_includes.h b/ext/interbase/php_ibase_includes.h
index d1dc5510a3d..4219913fc16 100644
--- a/ext/interbase/php_ibase_includes.h
+++ b/ext/interbase/php_ibase_includes.h
@@ -35,8 +35,7 @@
 
 #define IB_STATUS (IBG(status))
 
-/* XXX ZEND_DEBUG_ is misleading, it should be something like IBASE_DEBUG. */
-#ifdef ZEND_DEBUG_
+#ifdef IBASE_DEBUG
 #define IBDEBUG(a) php_printf("::: %s (%d)\n", a, __LINE__);
 #endif