diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index 15d585d5..1f015319 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -1,12 +1,14 @@
 name: Build and Test
-on: [push, pull_request]
+on:
+  pull_request:
+  push:
 jobs:
   build:
     name: Go CI
     runs-on: ubuntu-latest
     steps:
       - name: Set up Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
           go-version: 1.19
       - name: Check out source
diff --git a/base58/README.md b/base58/README.md
index cc6e7295..40dba64f 100644
--- a/base58/README.md
+++ b/base58/README.md
@@ -1,7 +1,6 @@
 base58
 ==========
 
-[![Build Status](http://img.shields.io/travis/cosmos/btcutil.svg)](https://travis-ci.org/cosmos/btcutil)
 [![ISC License](http://img.shields.io/badge/license-ISC-blue.svg)](http://copyfree.org)
 [![GoDoc](https://img.shields.io/badge/godoc-reference-blue.svg)](http://godoc.org/github.com/cosmos/btcutil/base58)
 
@@ -14,7 +13,7 @@ A comprehensive suite of tests is provided to ensure proper functionality.
 ## Installation and Updating
 
 ```bash
-$ go get -u github.com/cosmos/btcutil/base58
+go get -u github.com/cosmos/btcutil/base58
 ```
 
 ## Examples
diff --git a/base58/base58.go b/base58/base58.go
index 8ee59567..bd0ea47c 100644
--- a/base58/base58.go
+++ b/base58/base58.go
@@ -55,6 +55,10 @@ func Decode(b string) []byte {
 
 		total := uint64(0)
 		for _, v := range t[:n] {
+			if v > 255 {
+				return []byte("")
+			}
+
 			tmp := b58[v]
 			if tmp == 255 {
 				return []byte("")
diff --git a/base58/base58_test.go b/base58/base58_test.go
index ff420f1f..62b0e141 100644
--- a/base58/base58_test.go
+++ b/base58/base58_test.go
@@ -43,6 +43,8 @@ var invalidStringTests = []struct {
 	{"4kl8", ""},
 	{"0OIl", ""},
 	{"!@#$%^&*()-_=+~`", ""},
+	{"abcd\xd80", ""},
+	{"abcd\U000020BF", ""},
 }
 
 var hexTests = []struct {
diff --git a/base58/base58check.go b/base58/base58check.go
index 7cdafeee..402c3233 100644
--- a/base58/base58check.go
+++ b/base58/base58check.go
@@ -28,7 +28,7 @@ func checksum(input []byte) (cksum [4]byte) {
 func CheckEncode(input []byte, version byte) string {
 	b := make([]byte, 0, 1+len(input)+4)
 	b = append(b, version)
-	b = append(b, input[:]...)
+	b = append(b, input...)
 	cksum := checksum(b)
 	b = append(b, cksum[:]...)
 	return Encode(b)
diff --git a/base58/base58check_test.go b/base58/base58check_test.go
index 6981122e..d0183d23 100644
--- a/base58/base58check_test.go
+++ b/base58/base58check_test.go
@@ -37,11 +37,14 @@ func TestBase58Check(t *testing.T) {
 
 		// test decoding
 		res, version, err := base58.CheckDecode(test.out)
-		if err != nil {
+		switch {
+		case err != nil:
 			t.Errorf("CheckDecode test #%d failed with err: %v", x, err)
-		} else if version != test.version {
+
+		case version != test.version:
 			t.Errorf("CheckDecode test #%d failed: got version: %d want: %d", x, version, test.version)
-		} else if string(res) != test.in {
+
+		case string(res) != test.in:
 			t.Errorf("CheckDecode test #%d failed: got: %s want: %s", x, res, test.in)
 		}
 	}
@@ -56,7 +59,7 @@ func TestBase58Check(t *testing.T) {
 	// bytes are missing).
 	testString := ""
 	for len := 0; len < 4; len++ {
-		testString = testString + "x"
+		testString += "x"
 		_, _, err = base58.CheckDecode(testString)
 		if err != base58.ErrInvalidFormat {
 			t.Error("Checkdecode test failed, expected ErrInvalidFormat")