diff --git a/src/charset.c b/src/charset.c
index b19e344..eeebf17 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -555,7 +555,7 @@ load_charset_map_from_vector (struct charset *charset, Lisp_Object vec, int cont
 
   if (len % 2 == 1)
     {
-      add_to_log ("Failure in loading charset map: %V", vec, Qnil);
+      add_to_log ("Failure in loading charset map: %V", vec);
       return;
     }
 
diff --git a/src/image.c b/src/image.c
index 066db74..313419b 100644
--- a/src/image.c
+++ b/src/image.c
@@ -629,16 +629,19 @@ valid_image_p (Lisp_Object object)
 }
 
 
-/* Log error message with format string FORMAT and argument ARG.
+/* Log error message with format string FORMAT and trailing arguments.
    Signaling an error, e.g. when an image cannot be loaded, is not a
    good idea because this would interrupt redisplay, and the error
    message display would lead to another redisplay.  This function
    therefore simply displays a message.  */
 
 static void
-image_error (const char *format, Lisp_Object arg1, Lisp_Object arg2)
+image_error (const char *format, ...)
 {
-  add_to_log (format, arg1, arg2);
+  va_list ap;
+  va_start (ap, format);
+  vadd_to_log (format, ap);
+  va_end (ap);
 }