diff --git a/wholenumber/errors.go b/wholenumber/errors.go
deleted file mode 100644
index 4b65240..0000000
--- a/wholenumber/errors.go
+++ /dev/null
@@ -1,19 +0,0 @@
-package rfc8259wholenumber
-
-import (
-	"sourcecode.social/reiver/go-erorr"
-)
-
-const (
-	errNilDestination      = erorr.Error("rfc8259: nil destination")
-	errNilRuneScanner      = erorr.Error("rfc8259: nil rune-scanner")
-	errUnexpectedEndOfFile = erorr.Error("rfc8259: unexpected end-of-file")
-)
-
-func errProblemReadingRune(err error) error {
-	return erorr.Errorf("rfc8259: the JSON parser had a problem — problem reading rune: %w", err)
-}
-
-func errProblemUnreadingRune(err error, r rune) error {
-	return erorr.Errorf("rfc8259: the JSON parser had an internal-error — problem unreading rune %q (%U): %w", r, r, err)
-}
diff --git a/wholenumber/parse.go b/wholenumber/parse.go
index 33dd2e2..f3ef4eb 100644
--- a/wholenumber/parse.go
+++ b/wholenumber/parse.go
@@ -4,6 +4,8 @@ import (
 	"io"
 
 	"sourcecode.social/reiver/go-erorr"
+
+	"sourcecode.social/reiver/go-rfc8259/errors"
 )
 
 // Parse tries to parse the JSON whole-number literal.
@@ -37,10 +39,10 @@ import (
 //	fmt.Printf("dst = %#v\n", dst)
 func Parse(runescanner io.RuneScanner, dst *WholeNumber) error {
 	if nil == runescanner {
-		return errNilRuneScanner
+		return rfc8259errors.ErrNilRuneScanner
 	}
 	if nil == dst {
-		return errNilDestination
+		return rfc8259errors.ErrNilDestination
 	}
 
 	var buffer [256]byte
@@ -54,9 +56,9 @@ func Parse(runescanner io.RuneScanner, dst *WholeNumber) error {
 			r, _, err = runescanner.ReadRune()
 			if nil != err {
 				if io.EOF == err {
-					return errUnexpectedEndOfFile
+					return rfc8259errors.ErrUnexpectedEndOfFile
 				}
-				return errProblemReadingRune(err)
+				return rfc8259errors.ErrProblemReadingRune(err)
 			}
 		}
 
@@ -79,7 +81,7 @@ func Parse(runescanner io.RuneScanner, dst *WholeNumber) error {
 
 			r, _, err = runescanner.ReadRune()
 			if nil != err && io.EOF != err {
-				return errProblemReadingRune(err)
+				return rfc8259errors.ErrProblemReadingRune(err)
 			}
 			if io.EOF == err {
 	/////////////////////// BREAK
@@ -91,7 +93,7 @@ func Parse(runescanner io.RuneScanner, dst *WholeNumber) error {
 				p = append(p, string(r)...)
 			default:
 				if err := runescanner.UnreadRune(); nil != err {
-					return errProblemUnreadingRune(err, r)
+					return rfc8259errors.ErrProblemUnreadingRune(err, r)
 				}
 	/////////////////////// BREAK
 				break loop