diff --git a/en/signature-verify/README.md b/en/signature-verify/README.md
index 2a94a38a..4f7f116b 100644
--- a/en/signature-verify/README.md
+++ b/en/signature-verify/README.md
@@ -89,7 +89,7 @@ func main() {
 	publicKey := privateKey.Public()
 	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 	if !ok {
-		log.Fatal("error casting public key to ECDSA")
+		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 	}
 
 	publicKeyBytes := crypto.FromECDSAPub(publicKeyECDSA)
diff --git a/en/smart-contract-deploy/README.md b/en/smart-contract-deploy/README.md
index ab2e697d..fe9e5ca5 100644
--- a/en/smart-contract-deploy/README.md
+++ b/en/smart-contract-deploy/README.md
@@ -102,7 +102,7 @@ func main() {
 	publicKey := privateKey.Public()
 	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 	if !ok {
-		log.Fatal("error casting public key to ECDSA")
+		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 	}
 
 	fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
diff --git a/en/smart-contract-write/README.md b/en/smart-contract-write/README.md
index 5f6cffee..45e7c7f0 100644
--- a/en/smart-contract-write/README.md
+++ b/en/smart-contract-write/README.md
@@ -17,7 +17,7 @@ if err != nil {
 publicKey := privateKey.Public()
 publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 if !ok {
-  log.Fatal("error casting public key to ECDSA")
+  log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 }
 
 fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
@@ -158,7 +158,7 @@ func main() {
 	publicKey := privateKey.Public()
 	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 	if !ok {
-		log.Fatal("error casting public key to ECDSA")
+		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 	}
 
 	fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
diff --git a/en/transaction-raw-create/README.md b/en/transaction-raw-create/README.md
index 2a70e009..952da773 100644
--- a/en/transaction-raw-create/README.md
+++ b/en/transaction-raw-create/README.md
@@ -77,7 +77,7 @@ func main() {
 	publicKey := privateKey.Public()
 	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 	if !ok {
-		log.Fatal("error casting public key to ECDSA")
+		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 	}
 
 	fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
diff --git a/en/transfer-tokens/README.md b/en/transfer-tokens/README.md
index 386dc01d..8c2681b9 100644
--- a/en/transfer-tokens/README.md
+++ b/en/transfer-tokens/README.md
@@ -162,7 +162,7 @@ func main() {
 	publicKey := privateKey.Public()
 	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 	if !ok {
-		log.Fatal("error casting public key to ECDSA")
+		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 	}
 
 	fromAddress := crypto.PubkeyToAddress(*publicKeyECDSA)
diff --git a/en/wallet-generate/README.md b/en/wallet-generate/README.md
index 9138fc83..d4be0e33 100644
--- a/en/wallet-generate/README.md
+++ b/en/wallet-generate/README.md
@@ -38,7 +38,7 @@ Converting it to hex is a similar process that we went through with the private
 ```go
 publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 if !ok {
-  log.Fatal("error casting public key to ECDSA")
+  log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 }
 
 publicKeyBytes := crypto.FromECDSAPub(publicKeyECDSA)
@@ -91,7 +91,7 @@ func main() {
 	publicKey := privateKey.Public()
 	publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
 	if !ok {
-		log.Fatal("error casting public key to ECDSA")
+		log.Fatal("cannot assert type: publicKey is not of type *ecdsa.PublicKey")
 	}
 
 	publicKeyBytes := crypto.FromECDSAPub(publicKeyECDSA)