diff --git a/ethcore/res/ethereum/kovan.json b/ethcore/res/ethereum/kovan.json
index 281267135..453974eaf 100644
--- a/ethcore/res/ethereum/kovan.json
+++ b/ethcore/res/ethereum/kovan.json
@@ -43,7 +43,13 @@
 		"eip211Transition": 5067000,
 		"eip214Transition": 5067000,
 		"eip658Transition": 5067000,
-		"wasmActivationTransition": 6600000
+		"wasmActivationTransition": 6600000,
+		"eip145Transition": 9200000,
+		"eip1014Transition": 9200000,
+		"eip1052Transition": 9200000,
+		"eip1283Transition": 9200000,
+		"kip4Transition": 9200000,
+		"kip6Transition": 9200000
 	},
 	"genesis": {
 		"seal": {
diff --git a/ethcore/res/ethereum/ropsten.json b/ethcore/res/ethereum/ropsten.json
index 44c0dfe7b..09ebce8b2 100644
--- a/ethcore/res/ethereum/ropsten.json
+++ b/ethcore/res/ethereum/ropsten.json
@@ -9,12 +9,14 @@
 				"durationLimit": "0x0d",
 				"blockReward": {
 					"0": "0x4563918244F40000",
-					"1700000": "0x29A2241AF62C0000"
+					"1700000": "0x29A2241AF62C0000",
+					"4200000": "0x1BC16D674EC80000"
 				},
 				"homesteadTransition": 0,
 				"eip100bTransition": 1700000,
 				"difficultyBombDelays": {
-					"1700000": 3000000
+					"1700000": 3000000,
+					"4200000": 2000000
 				}
 			}
 		}
@@ -39,7 +41,11 @@
 		"eip140Transition": 1700000,
 		"eip211Transition": 1700000,
 		"eip214Transition": 1700000,
-		"eip658Transition": 1700000
+		"eip658Transition": 1700000,
+		"eip145Transition": 4200000,
+		"eip1014Transition": 4200000,
+		"eip1052Transition": 4200000,
+		"eip1283Transition": 4200000
 	},
 	"genesis": {
 		"seal": {
diff --git a/ethcore/src/json_tests/difficulty.rs b/ethcore/src/json_tests/difficulty.rs
index 0de1f1777..23a855945 100644
--- a/ethcore/src/json_tests/difficulty.rs
+++ b/ethcore/src/json_tests/difficulty.rs
@@ -95,10 +95,11 @@ mod difficulty_test_foundation {
 	declare_test!{DifficultyTests_difficultyMainNetwork, "BasicTests/difficultyMainNetwork.json"}
 }
 
-mod difficulty_test_ropsten {
-	difficulty_json_test_nopath!(new_ropsten_test);
-	declare_test!{DifficultyTests_difficultyRopsten, "BasicTests/difficultyRopsten.json"}
-}
+// Disabling Ropsten diff tests; waiting for upstream ethereum/tests Constantinople update
+//mod difficulty_test_ropsten {
+//	difficulty_json_test_nopath!(new_ropsten_test);
+//	declare_test!{DifficultyTests_difficultyRopsten, "BasicTests/difficultyRopsten.json"}
+//}
 
 mod difficulty_test_frontier {
 	difficulty_json_test_nopath!(new_frontier_test);