Update changelog.
diff --git a/Changelog b/Changelog
index d047c87..8ef0b83 100644
--- a/Changelog
+++ b/Changelog
@@ -1,3 +1,6 @@
+2018-09-09:
+  Fix bug where large hex literals would lose their minus sign.
+
 2013-12-23:
   Fix compilation for ARMv8 64bit (used wrong define).