diff --git a/codec/manager.go b/codec/manager.go
index 6fb48aaad9f8..608bbcabc0fe 100644
--- a/codec/manager.go
+++ b/codec/manager.go
@@ -13,6 +13,8 @@ import (
 )
 
 const (
+	VersionSize = wrappers.ShortLen
+
 	// default max size, in bytes, of something being marshalled by Marshal()
 	defaultMaxSize = 256 * units.KiB
 
@@ -102,8 +104,8 @@ func (m *manager) Size(version uint16, value interface{}) (int, error) {
 
 	res, err := c.Size(value)
 
-	// Add [wrappers.ShortLen] for the codec version
-	return wrappers.ShortLen + res, err
+	// Add [VersionSize] for the codec version
+	return VersionSize + res, err
 }
 
 // To marshal an interface, [value] must be a pointer to the interface.
diff --git a/codec/reflectcodec/type_codec.go b/codec/reflectcodec/type_codec.go
index 3306f9ccbd7c..c5ce970a8054 100644
--- a/codec/reflectcodec/type_codec.go
+++ b/codec/reflectcodec/type_codec.go
@@ -25,8 +25,6 @@ const (
 var (
 	_ codec.Codec = (*genericCodec)(nil)
 
-	errMarshalNil              = errors.New("can't marshal nil pointer or interface")
-	errUnmarshalNil            = errors.New("can't unmarshal nil")
 	errNeedPointer             = errors.New("argument to unmarshal must be a pointer")
 	errRecursiveInterfaceTypes = errors.New("recursive interface types")
 )
@@ -84,7 +82,7 @@ func New(typer TypeCodec, tagNames []string) codec.Codec {
 
 func (c *genericCodec) Size(value interface{}) (int, error) {
 	if value == nil {
-		return 0, errMarshalNil // can't marshal nil
+		return 0, codec.ErrMarshalNil
 	}
 
 	size, _, err := c.size(reflect.ValueOf(value), nil /*=typeStack*/)
@@ -120,14 +118,14 @@ func (c *genericCodec) size(
 		return wrappers.StringLen(value.String()), false, nil
 	case reflect.Ptr:
 		if value.IsNil() {
-			return 0, false, errMarshalNil
+			return 0, false, codec.ErrMarshalNil
 		}
 
 		return c.size(value.Elem(), typeStack)
 
 	case reflect.Interface:
 		if value.IsNil() {
-			return 0, false, errMarshalNil
+			return 0, false, codec.ErrMarshalNil
 		}
 
 		underlyingValue := value.Interface()
@@ -294,7 +292,7 @@ func (c *genericCodec) size(
 // To marshal an interface, [value] must be a pointer to the interface
 func (c *genericCodec) MarshalInto(value interface{}, p *wrappers.Packer) error {
 	if value == nil {
-		return errMarshalNil // can't marshal nil
+		return codec.ErrMarshalNil
 	}
 
 	return c.marshal(reflect.ValueOf(value), p, nil /*=typeStack*/)
@@ -341,13 +339,13 @@ func (c *genericCodec) marshal(
 		return p.Err
 	case reflect.Ptr:
 		if value.IsNil() {
-			return errMarshalNil
+			return codec.ErrMarshalNil
 		}
 
 		return c.marshal(value.Elem(), p, typeStack)
 	case reflect.Interface:
 		if value.IsNil() {
-			return errMarshalNil
+			return codec.ErrMarshalNil
 		}
 
 		underlyingValue := value.Interface()
@@ -502,7 +500,7 @@ func (c *genericCodec) marshal(
 // interface
 func (c *genericCodec) Unmarshal(bytes []byte, dest interface{}) error {
 	if dest == nil {
-		return errUnmarshalNil
+		return codec.ErrUnmarshalNil
 	}
 
 	p := wrappers.Packer{
diff --git a/vms/platformvm/state/metadata_validator.go b/vms/platformvm/state/metadata_validator.go
index 0c725368505b..340c7205350a 100644
--- a/vms/platformvm/state/metadata_validator.go
+++ b/vms/platformvm/state/metadata_validator.go
@@ -6,6 +6,7 @@ package state
 import (
 	"time"
 
+	"github.com/ava-labs/avalanchego/codec"
 	"github.com/ava-labs/avalanchego/database"
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/constants"
@@ -17,7 +18,7 @@ import (
 // [preDelegateeRewardMetadata].
 //
 // CodecVersionLen + UpDurationLen + LastUpdatedLen + PotentialRewardLen
-const preDelegateeRewardSize = wrappers.ShortLen + 3*wrappers.LongLen
+const preDelegateeRewardSize = codec.VersionSize + 3*wrappers.LongLen
 
 var _ validatorState = (*metadata)(nil)