diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index d1216e4ade2f..629ad32d4708 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -43,16 +43,16 @@ static void conf_warning(const char *fmt, ...)
 	conf_warnings++;
 }
 
-static void conf_default_message_callback(const char *fmt, va_list ap)
+static void conf_default_message_callback(const char *s)
 {
 	printf("#\n# ");
-	vprintf(fmt, ap);
+	printf("%s", s);
 	printf("\n#\n");
 }
 
-static void (*conf_message_callback) (const char *fmt, va_list ap) =
+static void (*conf_message_callback)(const char *s) =
 	conf_default_message_callback;
-void conf_set_message_callback(void (*fn) (const char *fmt, va_list ap))
+void conf_set_message_callback(void (*fn)(const char *s))
 {
 	conf_message_callback = fn;
 }
@@ -60,10 +60,15 @@ void conf_set_message_callback(void (*fn) (const char *fmt, va_list ap))
 static void conf_message(const char *fmt, ...)
 {
 	va_list ap;
+	char buf[4096];
+
+	if (!conf_message_callback)
+		return;
 
 	va_start(ap, fmt);
-	if (conf_message_callback)
-		conf_message_callback(fmt, ap);
+
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	conf_message_callback(buf);
 	va_end(ap);
 }
 
diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index a8b7a330587e..cf4510a2bdc7 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -10,7 +10,7 @@ int conf_write(const char *name);
 int conf_write_autoconf(void);
 bool conf_get_changed(void);
 void conf_set_changed_callback(void (*fn)(void));
-void conf_set_message_callback(void (*fn)(const char *fmt, va_list ap));
+void conf_set_message_callback(void (*fn)(const char *s));
 
 /* menu.c */
 extern struct menu rootmenu;
diff --git a/scripts/kconfig/mconf.c b/scripts/kconfig/mconf.c
index 5294ed159b98..b8f3b607962a 100644
--- a/scripts/kconfig/mconf.c
+++ b/scripts/kconfig/mconf.c
@@ -772,16 +772,13 @@ static void show_helptext(const char *title, const char *text)
 	show_textbox(title, text, 0, 0);
 }
 
-static void conf_message_callback(const char *fmt, va_list ap)
+static void conf_message_callback(const char *s)
 {
-	char buf[PATH_MAX+1];
-
-	vsnprintf(buf, sizeof(buf), fmt, ap);
 	if (save_and_exit) {
 		if (!silent)
-			printf("%s", buf);
+			printf("%s", s);
 	} else {
-		show_textbox(NULL, buf, 6, 60);
+		show_textbox(NULL, s, 6, 60);
 	}
 }
 
diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c
index 97b78445584b..5cbdb92e11b3 100644
--- a/scripts/kconfig/nconf.c
+++ b/scripts/kconfig/nconf.c
@@ -1210,12 +1210,9 @@ static void conf(struct menu *menu)
 	}
 }
 
-static void conf_message_callback(const char *fmt, va_list ap)
+static void conf_message_callback(const char *s)
 {
-	char buf[1024];
-
-	vsnprintf(buf, sizeof(buf), fmt, ap);
-	btn_dialog(main_window, buf, 1, "<OK>");
+	btn_dialog(main_window, s, 1, "<OK>");
 }
 
 static void show_help(struct menu *menu)