Added missing include.
diff --git a/MagickCore/display.c b/MagickCore/display.c
index fefa7e7..7ea9f28 100644
--- a/MagickCore/display.c
+++ b/MagickCore/display.c
@@ -87,6 +87,7 @@
 #include "MagickCore/statistic.h"
 #include "MagickCore/string_.h"
 #include "MagickCore/string-private.h"
+#include "MagickCore/transform.h"
 #include "MagickCore/transform-private.h"
 #include "MagickCore/threshold.h"
 #include "MagickCore/utility.h"