diff --git a/accounts/accounts_test.go b/accounts/accounts_test.go
index 02dd74c8a2..4a1d1b8484 100644
--- a/accounts/accounts_test.go
+++ b/accounts/accounts_test.go
@@ -120,7 +120,7 @@ func TestSignRace(t *testing.T) {
 	}
 
 	if err := am.TimedUnlock(a1.Address, "", 15*time.Millisecond); err != nil {
-		t.Fatalf("could not unlock the test account", err)
+		t.Fatal("could not unlock the test account", err)
 	}
 	end := time.Now().Add(500 * time.Millisecond)
 	for time.Now().Before(end) {
diff --git a/accounts/key_store_passphrase.go b/accounts/key_store_passphrase.go
index cb00b90af3..3ee86588e3 100644
--- a/accounts/key_store_passphrase.go
+++ b/accounts/key_store_passphrase.go
@@ -295,13 +295,13 @@ func getKDFKey(cryptoJSON cryptoJSON, auth string) ([]byte, error) {
 		c := ensureInt(cryptoJSON.KDFParams["c"])
 		prf := cryptoJSON.KDFParams["prf"].(string)
 		if prf != "hmac-sha256" {
-			return nil, fmt.Errorf("Unsupported PBKDF2 PRF: ", prf)
+			return nil, fmt.Errorf("Unsupported PBKDF2 PRF: %s", prf)
 		}
 		key := pbkdf2.Key(authArray, salt, c, dkLen, sha256.New)
 		return key, nil
 	}
 
-	return nil, fmt.Errorf("Unsupported KDF: ", cryptoJSON.KDF)
+	return nil, fmt.Errorf("Unsupported KDF: %s", cryptoJSON.KDF)
 }
 
 // TODO: can we do without this when unmarshalling dynamic JSON?
diff --git a/accounts/key_store_passphrase_test.go b/accounts/key_store_passphrase_test.go
index afa751d449..6ff3ae4225 100644
--- a/accounts/key_store_passphrase_test.go
+++ b/accounts/key_store_passphrase_test.go
@@ -32,7 +32,7 @@ func TestKeyEncryptDecrypt(t *testing.T) {
 	for i := 0; i < 3; i++ {
 		// Try a bad password first
 		if _, err := DecryptKey(keyjson, password+"bad"); err == nil {
-			t.Error("test %d: json key decrypted with bad password", i)
+			t.Errorf("test %d: json key decrypted with bad password", i)
 		}
 		// Decrypt with the correct password
 		key, err := DecryptKey(keyjson, password)
@@ -45,7 +45,7 @@ func TestKeyEncryptDecrypt(t *testing.T) {
 		// Recrypt with a new password and start over
 		password += "new data appended"
 		if keyjson, err = EncryptKey(key, password, LightScryptN, LightScryptP); err != nil {
-			t.Errorf("test %d: failed to recrypt key %v", err)
+			t.Errorf("test %d: failed to recrypt key %v", i, err)
 		}
 	}
 }