diff --git a/History.txt b/History.txt
index 5af71f78d8e8d2e749516a8e1ff40ffdf9a11543..53a9f2f6da74dc0a863cf606730544e0a3966eee 100755
--- a/History.txt
+++ b/History.txt
@@ -3,6 +3,7 @@
 * Avoid call to rb_class2name() during GC. Fixes #21
 * Use release mode, unless extconf.rb is called with --enable-debug,
   so that all FXTRACE() and FXASSERT() calls are skiped, per default.
+* Remove self made GC detection by ruby's rb_during_gc().
 
 === 1.6.31 / 2015-07-21