diff --git a/ChangeLog b/ChangeLog
index ba6d04f2..8fab4542 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+7/3/08 started 7.15.0
+- MAGIC numbers should be unsigned
+
 25/1/08 started 7.14.0
 - bump all version numbers for new stable
 - better CMYK JPEG read (thanks Ole)
diff --git a/include/vips/vips.h b/include/vips/vips.h
index 0ca40009..9091f296 100644
--- a/include/vips/vips.h
+++ b/include/vips/vips.h
@@ -93,8 +93,8 @@ extern "C" {
  *   intel order: byte 0 = b6
  *   SPARC order: byte 0 = 08
  */
-#define IM_MAGIC_INTEL (0xb6a6f208)
-#define IM_MAGIC_SPARC (0x08f2a6b6)
+#define IM_MAGIC_INTEL (0xb6a6f208U)
+#define IM_MAGIC_SPARC (0x08f2a6b6U)
 
 /* Private to iofuncs: the image size above which we switch from
  * mmap()-whole-image behaviour to mmap()-window, plus window margins.