diff --git a/encoding/yaml/yaml_test.go b/encoding/yaml/yaml_test.go
index ae506bb019c..f71838d78c5 100644
--- a/encoding/yaml/yaml_test.go
+++ b/encoding/yaml/yaml_test.go
@@ -184,6 +184,7 @@ func TestYAMLValues(t *testing.T) {
 		{`"-.Inf"`, `"-.Inf"`},
 		{`"2002"`, `"2002"`},
 		{`"685_230.15"`, `"685_230.15"`},
+		{`"0x123456789012345678901234567890"`, `"0x123456789012345678901234567890"`},
 
 		// Legacy values.format.
 		{`"no"`, `"no"`},
diff --git a/internal/encoding/yaml/encode.go b/internal/encoding/yaml/encode.go
index 55871dab314..87aec6e417a 100644
--- a/internal/encoding/yaml/encode.go
+++ b/internal/encoding/yaml/encode.go
@@ -164,7 +164,7 @@ func shouldQuote(str string) bool {
 
 // This regular expression conservatively matches any date, time string,
 // or base60 float.
-var useQuote = regexp.MustCompile(`^[\-+0-9:\. \t]+([-:]|[tT])[\-+0-9:\. \t]+[zZ]?$`)
+var useQuote = regexp.MustCompile(`^[\-+0-9:\. \t]+([-:]|[tT])[\-+0-9:\. \t]+[zZ]?$|^0x[a-fA-F0-9]+$`)
 
 // legacyStrings contains a map of fixed strings with special meaning for any
 // type in the YAML Tag registry (https://yaml.org/type/index.html) as used
diff --git a/internal/encoding/yaml/encode_test.go b/internal/encoding/yaml/encode_test.go
index a21a21f799f..d26ee4d417c 100644
--- a/internal/encoding/yaml/encode_test.go
+++ b/internal/encoding/yaml/encode_test.go
@@ -36,6 +36,8 @@ func TestEncodeFile(t *testing.T) {
 		in: `
 		package test
 
+		bighex: "0x1234567890123456789001234567890"
+		nothex: "0x1234567890123456789001234567890zz"
 		seq: [
 			1, 2, 3, {
 				a: 1
@@ -50,6 +52,8 @@ func TestEncodeFile(t *testing.T) {
 		}
 		`,
 		out: `
+bighex: "0x1234567890123456789001234567890"
+nothex: 0x1234567890123456789001234567890zz
 seq:
   - 1
   - 2