diff --git a/ethcore/res/ethereum/kovan.json b/ethcore/res/ethereum/kovan.json
index 69f7e8b60..0d00478c5 100644
--- a/ethcore/res/ethereum/kovan.json
+++ b/ethcore/res/ethereum/kovan.json
@@ -36,13 +36,14 @@
 		"forkCanonHash": "0x0a66d93c2f727dca618fabaf70c39b37018c73d78b939d8b11efbbd09034778f",
 		"eip155Transition": 1000000,
 		"maxCodeSize": 24576,
-		"maxCodeSizeTransition": 6500000,
+		"maxCodeSizeTransition": 6600000,
 		"validateChainIdTransition": 1000000,
 		"validateReceiptsTransition" : 1000000,
 		"eip140Transition": 5067000,
 		"eip211Transition": 5067000,
 		"eip214Transition": 5067000,
-		"eip658Transition": 5067000
+		"eip658Transition": 5067000,
+		"wasmActivationTransition": 6600000
 	},
 	"genesis": {
 		"seal": {
diff --git a/util/version/Cargo.toml b/util/version/Cargo.toml
index 0b0fefc25..e782b9d3e 100644
--- a/util/version/Cargo.toml
+++ b/util/version/Cargo.toml
@@ -13,13 +13,13 @@ build = "build.rs"
 track = "stable"
 
 # Indicates a critical release in this track (i.e. consensus issue)
-critical = false
+critical = true
 
 # Latest supported fork blocks for various networks. Used ONLY by auto-updater.
 [package.metadata.forks]
 foundation = 4370000
 ropsten = 10
-kovan = 5067000
+kovan = 6600000
 
 [dependencies]
 ethcore-bytes = { path = "../bytes" }