diff --git a/cmd/geth/consolecmd.go b/cmd/geth/consolecmd.go
index 526ede9619..7e68952859 100644
--- a/cmd/geth/consolecmd.go
+++ b/cmd/geth/consolecmd.go
@@ -152,7 +152,7 @@ func remoteConsole(ctx *cli.Context) error {
 func ephemeralConsole(ctx *cli.Context) error {
 	var b strings.Builder
 	for _, file := range ctx.Args().Slice() {
-		b.Write([]byte(fmt.Sprintf("loadScript('%s');", file)))
+		b.Write(fmt.Appendf(nil, "loadScript('%s');", file))
 	}
 	utils.Fatalf(`The "js" command is deprecated. Please use the following instead:
 geth --exec "%s" console`, b.String())
diff --git a/common/math/big.go b/common/math/big.go
index 721b297c9c..526fcc293c 100644
--- a/common/math/big.go
+++ b/common/math/big.go
@@ -75,7 +75,7 @@ func (i *HexOrDecimal256) MarshalText() ([]byte, error) {
 	if i == nil {
 		return []byte("0x0"), nil
 	}
-	return []byte(fmt.Sprintf("%#x", (*big.Int)(i))), nil
+	return fmt.Appendf(nil, "%#x", (*big.Int)(i)), nil
 }
 
 // Decimal256 unmarshals big.Int as a decimal string. When unmarshalling,
diff --git a/common/math/integer.go b/common/math/integer.go
index da01c0a08e..dafaf721c3 100644
--- a/common/math/integer.go
+++ b/common/math/integer.go
@@ -64,7 +64,7 @@ func (i *HexOrDecimal64) UnmarshalText(input []byte) error {
 
 // MarshalText implements encoding.TextMarshaler.
 func (i HexOrDecimal64) MarshalText() ([]byte, error) {
-	return []byte(fmt.Sprintf("%#x", uint64(i))), nil
+	return fmt.Appendf(nil, "%#x", uint64(i)), nil
 }
 
 // ParseUint64 parses s as an integer in decimal or hexadecimal syntax.