diff --git a/src/cmd/compile/internal/ssa/compile.go b/src/cmd/compile/internal/ssa/compile.go
index 5e898ab96f..3be2cc7c37 100644
--- a/src/cmd/compile/internal/ssa/compile.go
+++ b/src/cmd/compile/internal/ssa/compile.go
@@ -5,7 +5,6 @@
 package ssa
 
 import (
-	"bytes"
 	"cmd/internal/src"
 	"fmt"
 	"hash/crc32"
@@ -152,7 +151,7 @@ func Compile(f *Func) {
 			keys = append(keys, key)
 		}
 		sort.Strings(keys)
-		buf := new(bytes.Buffer)
+		buf := new(strings.Builder)
 		fmt.Fprintf(buf, "%s: ", f.Name)
 		for _, key := range keys {
 			fmt.Fprintf(buf, "%s=%d ", key, f.ruleMatches[key])
diff --git a/src/cmd/compile/internal/ssa/debug_lines_test.go b/src/cmd/compile/internal/ssa/debug_lines_test.go
index 7b8b5eb180..23b511ddb2 100644
--- a/src/cmd/compile/internal/ssa/debug_lines_test.go
+++ b/src/cmd/compile/internal/ssa/debug_lines_test.go
@@ -11,6 +11,7 @@ import (
 	"internal/buildcfg"
 	"runtime"
 	"sort"
+	"strings"
 
 	"fmt"
 	"internal/testenv"
@@ -157,7 +158,7 @@ func compileAndDump(t *testing.T, file, function, moreGCFlags string) []byte {
 		fmt.Printf("About to run %s\n", asCommandLine("", cmd))
 	}
 
-	var stdout, stderr bytes.Buffer
+	var stdout, stderr strings.Builder
 	cmd.Stdout = &stdout
 	cmd.Stderr = &stderr
 
diff --git a/src/cmd/compile/internal/ssa/debug_test.go b/src/cmd/compile/internal/ssa/debug_test.go
index c807863ea6..f3f8eeeb41 100644
--- a/src/cmd/compile/internal/ssa/debug_test.go
+++ b/src/cmd/compile/internal/ssa/debug_test.go
@@ -5,7 +5,6 @@
 package ssa_test
 
 import (
-	"bytes"
 	"flag"
 	"fmt"
 	"internal/testenv"
@@ -298,7 +297,7 @@ func runDbgr(dbg dbgr, maxNext int) *nextHist {
 }
 
 func runGo(t *testing.T, dir string, args ...string) string {
-	var stdout, stderr bytes.Buffer
+	var stdout, stderr strings.Builder
 	cmd := exec.Command(testenv.GoToolPath(t), args...)
 	cmd.Dir = dir
 	if *dryrun {
diff --git a/src/cmd/compile/internal/ssa/gen/main.go b/src/cmd/compile/internal/ssa/gen/main.go
index 2cf0a919fa..b1a7cf9f6f 100644
--- a/src/cmd/compile/internal/ssa/gen/main.go
+++ b/src/cmd/compile/internal/ssa/gen/main.go
@@ -94,7 +94,7 @@ type regInfo struct {
 type regMask uint64
 
 func (a arch) regMaskComment(r regMask) string {
-	var buf bytes.Buffer
+	var buf strings.Builder
 	for i := uint64(0); r != 0; i++ {
 		if r&1 != 0 {
 			if buf.Len() == 0 {
diff --git a/src/cmd/compile/internal/ssa/html.go b/src/cmd/compile/internal/ssa/html.go
index 1e6060ab32..c3950697d3 100644
--- a/src/cmd/compile/internal/ssa/html.go
+++ b/src/cmd/compile/internal/ssa/html.go
@@ -848,7 +848,7 @@ func (w *HTMLWriter) WriteSources(phase string, all []*FuncLines) {
 	if w == nil {
 		return // avoid generating HTML just to discard it
 	}
-	var buf bytes.Buffer
+	var buf strings.Builder
 	fmt.Fprint(&buf, "<div class=\"lines\" style=\"width: 8%\">")
 	filename := ""
 	for _, fl := range all {
@@ -890,7 +890,7 @@ func (w *HTMLWriter) WriteAST(phase string, buf *bytes.Buffer) {
 		return // avoid generating HTML just to discard it
 	}
 	lines := strings.Split(buf.String(), "\n")
-	var out bytes.Buffer
+	var out strings.Builder
 
 	fmt.Fprint(&out, "<div>")
 	for _, l := range lines {
@@ -1053,7 +1053,7 @@ func (b *Block) LongHTML() string {
 }
 
 func (f *Func) HTML(phase string, dot *dotWriter) string {
-	buf := new(bytes.Buffer)
+	buf := new(strings.Builder)
 	if dot != nil {
 		dot.writeFuncSVG(buf, phase, f)
 	}
@@ -1082,7 +1082,7 @@ func (d *dotWriter) writeFuncSVG(w io.Writer, phase string, f *Func) {
 	}
 	buf := new(bytes.Buffer)
 	cmd.Stdout = buf
-	bufErr := new(bytes.Buffer)
+	bufErr := new(strings.Builder)
 	cmd.Stderr = bufErr
 	err = cmd.Start()
 	if err != nil {
diff --git a/src/cmd/compile/internal/ssa/print.go b/src/cmd/compile/internal/ssa/print.go
index aea9ce9e33..85ba6b72c6 100644
--- a/src/cmd/compile/internal/ssa/print.go
+++ b/src/cmd/compile/internal/ssa/print.go
@@ -5,9 +5,9 @@
 package ssa
 
 import (
-	"bytes"
 	"fmt"
 	"io"
+	"strings"
 
 	"cmd/internal/notsha256"
 	"cmd/internal/src"
@@ -25,7 +25,7 @@ func hashFunc(f *Func) []byte {
 }
 
 func (f *Func) String() string {
-	var buf bytes.Buffer
+	var buf strings.Builder
 	p := stringFuncPrinter{w: &buf, printDead: true}
 	fprintFunc(p, f)
 	return buf.String()