diff --git a/ChangeLog b/ChangeLog
index 8a31ce7239..91522d2d6f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jan 28 15:12:22 2014  Zachary Scott  <e@zzak.io>
+
+	* ext/zlib/zlib.c (rb_zlib_adler32): [DOC] Add example for adler32
+	  Patch by Vajrasky Kok [Bug #9307] [ci skip]
+
 Tue Jan 28 08:56:00 2014  Charlie Somerville  <charliesome@ruby-lang.org>
 
 	* compile.c (iseq_build_from_ary_body): Use :blockptr instead of :block
diff --git a/ext/zlib/zlib.c b/ext/zlib/zlib.c
index 391bec1722..c0f52c23cc 100644
--- a/ext/zlib/zlib.c
+++ b/ext/zlib/zlib.c
@@ -429,7 +429,14 @@ do_checksum(argc, argv, func)
  * +adler+. If +string+ is omitted, it returns the Adler-32 initial value. If
  * +adler+ is omitted, it assumes that the initial value is given to +adler+.
  *
- * FIXME: expression.
+ * Example usage:
+ *
+ *   require "zlib"
+ *
+ *   data = "foo"
+ *   puts "Adler32 checksum: #{Zlib.adler32(data).to_s(16)}"
+ *   #=> Adler32 checksum: 2820145
+ *
  */
 static VALUE
 rb_zlib_adler32(int argc, VALUE *argv, VALUE klass)