diff --git a/contracts/exchange/CHANGELOG.json b/contracts/exchange/CHANGELOG.json
index 091d78b70b..fb345dbf7c 100644
--- a/contracts/exchange/CHANGELOG.json
+++ b/contracts/exchange/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "version": "2.1.9",
+        "changes": [
+            {
+                "note": "Use new/cheaper reentrancy guard/mutex",
+                "pr": 1699
+            }
+        ]
+    },
     {
         "timestamp": 1563193019,
         "version": "2.1.8",
diff --git a/contracts/utils/CHANGELOG.json b/contracts/utils/CHANGELOG.json
index f66bdd752f..d6404d8241 100644
--- a/contracts/utils/CHANGELOG.json
+++ b/contracts/utils/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "version": "3.1.10",
+        "changes": [
+            {
+                "note": "Change ReentrancyGuard implementation to cheaper one",
+                "pr": 1699
+            }
+        ]
+    },
     {
         "timestamp": 1563193019,
         "version": "3.1.9",