diff --git a/CHANGELOG.md b/CHANGELOG.md
index 41979bf..794cd8c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.2.1 / 2019-10-17
+
+* [BUGFIX] Fix regression in the implementation of `Registerer.Unregister`. #663
+
 ## 1.2.0 / 2019-10-15
 
 * [FEATURE] Support pushing to Pushgateway v0.10+. #652
diff --git a/VERSION b/VERSION
index 26aaba0..6085e94 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.2.0
+1.2.1