diff --git a/package/monkey/monkey.mk b/package/monkey/monkey.mk
index 2344f8c753..419750e47f 100644
--- a/package/monkey/monkey.mk
+++ b/package/monkey/monkey.mk
@@ -47,7 +47,7 @@ MONKEY_POST_INSTALL_TARGET_HOOKS += MONKEY_REMOVE_DANGLING_SYMLINK
 endif
 
 ifeq ($(BR2_ENABLE_DEBUG),y)
-MONKEY_CONF_OPT += --debug
+MONKEY_CONF_OPTS += --debug
 endif
 
 define MONKEY_CONFIGURE_CMDS