ChangeLog.md in digest-crc-0.6.3 vs ChangeLog.md in digest-crc-0.6.4

@@ -1,4 +1,9 @@
+### 0.6.4 / 2021-07-14
+
+* Silence potential method redefinition warnings when loading the C extensions.
+  (@ojab)
+
 ### 0.6.3 / 2020-12-19
 
 * Broaden rake dependency to >= 12.0.0, < 14.0.0` for ruby 2.7, which includes
   rake 13.x.