diff --git a/coders/dps.c b/coders/dps.c
index 9ddfa21..3206d68 100644
--- a/coders/dps.c
+++ b/coders/dps.c
@@ -155,12 +155,12 @@
     Open X server connection.
   */
   assert(image_info != (const ImageInfo *) NULL);
-  assert(image_info->signature == MagickSignature);
+  assert(image_info->signature == MagickCoreSignature);
   if (image_info->debug != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
       image_info->filename);
   assert(exception != (ExceptionInfo *) NULL);
-  assert(exception->signature == MagickSignature);
+  assert(exception->signature == MagickCoreSignature);
   display=XOpenDisplay(image_info->server_name);
   if (display == (Display *) NULL)
     return((Image *) NULL);