diff --git a/arshal_default.go b/arshal_default.go
index b353bc5..5bc64d3 100644
--- a/arshal_default.go
+++ b/arshal_default.go
@@ -612,14 +612,13 @@ func makeMapArshaler(t reflect.Type) *arshaler {
 
 	var fncs arshaler
 	var (
-		once    sync.Once
 		keyFncs *arshaler
 		valFncs *arshaler
 	)
-	init := func() {
+	initOnce := sync.OnceFunc(func() {
 		keyFncs = lookupArshaler(t.Key())
 		valFncs = lookupArshaler(t.Elem())
-	}
+	})
 	fncs.marshal = func(enc *jsontext.Encoder, va addressableValue, mo *jsonopts.Struct) error {
 		// Check for cycles.
 		xe := export.Encoder(enc)
@@ -661,7 +660,7 @@ func makeMapArshaler(t reflect.Type) *arshaler {
 			}
 		}
 
-		once.Do(init)
+		initOnce()
 		if err := enc.WriteToken(jsontext.ObjectStart); err != nil {
 			return err
 		}
@@ -792,7 +791,7 @@ func makeMapArshaler(t reflect.Type) *arshaler {
 			va.SetZero()
 			return nil
 		case '{':
-			once.Do(init)
+			initOnce()
 			if va.IsNil() {
 				va.Set(reflect.MakeMap(t))
 			}
@@ -900,19 +899,18 @@ func makeStructArshaler(t reflect.Type) *arshaler {
 
 	var fncs arshaler
 	var (
-		once    sync.Once
 		fields  structFields
 		errInit *SemanticError
 	)
-	init := func() {
+	initOnce := sync.OnceFunc(func() {
 		fields, errInit = makeStructFields(t)
-	}
+	})
 	fncs.marshal = func(enc *jsontext.Encoder, va addressableValue, mo *jsonopts.Struct) error {
 		xe := export.Encoder(enc)
 		if mo.Format != "" && mo.FormatDepth == xe.Tokens.Depth() {
 			return newInvalidFormatError("marshal", t, mo.Format)
 		}
-		once.Do(init)
+		initOnce()
 		if errInit != nil {
 			err := *errInit // shallow copy SemanticError
 			err.action = "marshal"
@@ -1080,7 +1078,7 @@ func makeStructArshaler(t reflect.Type) *arshaler {
 			va.SetZero()
 			return nil
 		case '{':
-			once.Do(init)
+			initOnce()
 			if errInit != nil {
 				err := *errInit // shallow copy SemanticError
 				err.action = "unmarshal"
@@ -1214,13 +1212,10 @@ func isLegacyEmpty(v addressableValue) bool {
 
 func makeSliceArshaler(t reflect.Type) *arshaler {
 	var fncs arshaler
-	var (
-		once    sync.Once
-		valFncs *arshaler
-	)
-	init := func() {
+	var valFncs *arshaler
+	initOnce := sync.OnceFunc(func() {
 		valFncs = lookupArshaler(t.Elem())
-	}
+	})
 	fncs.marshal = func(enc *jsontext.Encoder, va addressableValue, mo *jsonopts.Struct) error {
 		// Check for cycles.
 		xe := export.Encoder(enc)
@@ -1262,7 +1257,7 @@ func makeSliceArshaler(t reflect.Type) *arshaler {
 			}
 		}
 
-		once.Do(init)
+		initOnce()
 		if err := enc.WriteToken(jsontext.ArrayStart); err != nil {
 			return err
 		}
@@ -1303,7 +1298,7 @@ func makeSliceArshaler(t reflect.Type) *arshaler {
 			va.SetZero()
 			return nil
 		case '[':
-			once.Do(init)
+			initOnce()
 			unmarshal := valFncs.unmarshal
 			if uo.Unmarshalers != nil {
 				unmarshal, _ = uo.Unmarshalers.(*Unmarshalers).lookup(unmarshal, t.Elem())
@@ -1348,20 +1343,17 @@ func makeSliceArshaler(t reflect.Type) *arshaler {
 
 func makeArrayArshaler(t reflect.Type) *arshaler {
 	var fncs arshaler
-	var (
-		once    sync.Once
-		valFncs *arshaler
-	)
-	init := func() {
+	var valFncs *arshaler
+	initOnce := sync.OnceFunc(func() {
 		valFncs = lookupArshaler(t.Elem())
-	}
+	})
 	n := t.Len()
 	fncs.marshal = func(enc *jsontext.Encoder, va addressableValue, mo *jsonopts.Struct) error {
 		xe := export.Encoder(enc)
 		if mo.Format != "" && mo.FormatDepth == xe.Tokens.Depth() {
 			return newInvalidFormatError("marshal", t, mo.Format)
 		}
-		once.Do(init)
+		initOnce()
 		if err := enc.WriteToken(jsontext.ArrayStart); err != nil {
 			return err
 		}
@@ -1395,7 +1387,7 @@ func makeArrayArshaler(t reflect.Type) *arshaler {
 			va.SetZero()
 			return nil
 		case '[':
-			once.Do(init)
+			initOnce()
 			unmarshal := valFncs.unmarshal
 			if uo.Unmarshalers != nil {
 				unmarshal, _ = uo.Unmarshalers.(*Unmarshalers).lookup(unmarshal, t.Elem())
@@ -1441,13 +1433,10 @@ func makeArrayArshaler(t reflect.Type) *arshaler {
 
 func makePointerArshaler(t reflect.Type) *arshaler {
 	var fncs arshaler
-	var (
-		once    sync.Once
-		valFncs *arshaler
-	)
-	init := func() {
+	var valFncs *arshaler
+	initOnce := sync.OnceFunc(func() {
 		valFncs = lookupArshaler(t.Elem())
-	}
+	})
 	fncs.marshal = func(enc *jsontext.Encoder, va addressableValue, mo *jsonopts.Struct) error {
 		// Check for cycles.
 		xe := export.Encoder(enc)
@@ -1462,7 +1451,7 @@ func makePointerArshaler(t reflect.Type) *arshaler {
 		if va.IsNil() {
 			return enc.WriteToken(jsontext.Null)
 		}
-		once.Do(init)
+		initOnce()
 		marshal := valFncs.marshal
 		if mo.Marshalers != nil {
 			marshal, _ = mo.Marshalers.(*Marshalers).lookup(marshal, t.Elem())
@@ -1479,7 +1468,7 @@ func makePointerArshaler(t reflect.Type) *arshaler {
 			va.SetZero()
 			return nil
 		}
-		once.Do(init)
+		initOnce()
 		unmarshal := valFncs.unmarshal
 		if uo.Unmarshalers != nil {
 			unmarshal, _ = uo.Unmarshalers.(*Unmarshalers).lookup(unmarshal, t.Elem())