diff --git a/ddl/index.go b/ddl/index.go
index 833a825e24e30..07a3960eb07fc 100644
--- a/ddl/index.go
+++ b/ddl/index.go
@@ -101,7 +101,7 @@ func buildIndexColumns(ctx sessionctx.Context, columns []*model.ColumnInfo, inde
 			// The multiple column index and the unique index in which the length sum exceeds the maximum size
 			// will return an error instead produce a warning.
 			if ctx == nil || ctx.GetSessionVars().StrictSQLMode || mysql.HasUniKeyFlag(col.GetFlag()) || len(indexPartSpecifications) > 1 {
-				return nil, false, dbterror.ErrTooLongKey.GenWithStackByArgs(maxIndexLength)
+				return nil, false, dbterror.ErrTooLongKey.GenWithStackByArgs(sumLength, maxIndexLength)
 			}
 			// truncate index length and produce warning message in non-restrict sql mode.
 			colLenPerUint, err := getIndexColumnLength(col, 1)
@@ -110,7 +110,7 @@ func buildIndexColumns(ctx sessionctx.Context, columns []*model.ColumnInfo, inde
 			}
 			indexColLen = maxIndexLength / colLenPerUint
 			// produce warning message
-			ctx.GetSessionVars().StmtCtx.AppendWarning(dbterror.ErrTooLongKey.FastGenByArgs(maxIndexLength))
+			ctx.GetSessionVars().StmtCtx.AppendWarning(dbterror.ErrTooLongKey.FastGenByArgs(sumLength, maxIndexLength))
 		}
 
 		idxParts = append(idxParts, &model.IndexColumn{
@@ -149,7 +149,7 @@ func checkIndexPrefixLength(columns []*model.ColumnInfo, idxColumns []*model.Ind
 		return err
 	}
 	if idxLen > config.GetGlobalConfig().MaxIndexLength {
-		return dbterror.ErrTooLongKey.GenWithStackByArgs(config.GetGlobalConfig().MaxIndexLength)
+		return dbterror.ErrTooLongKey.GenWithStackByArgs(idxLen, config.GetGlobalConfig().MaxIndexLength)
 	}
 	return nil
 }
@@ -211,7 +211,7 @@ func checkIndexColumn(ctx sessionctx.Context, col *model.ColumnInfo, indexColumn
 	maxIndexLength := config.GetGlobalConfig().MaxIndexLength
 	if indexColumnLen > maxIndexLength && (ctx == nil || ctx.GetSessionVars().StrictSQLMode) {
 		// return error in strict sql mode
-		return dbterror.ErrTooLongKey.GenWithStackByArgs(maxIndexLength)
+		return dbterror.ErrTooLongKey.GenWithStackByArgs(indexColumnLen, maxIndexLength)
 	}
 	return nil
 }
diff --git a/ddl/serial_test.go b/ddl/serial_test.go
index 668b675a0b185..4d11db2b3409c 100644
--- a/ddl/serial_test.go
+++ b/ddl/serial_test.go
@@ -102,7 +102,7 @@ func TestChangeMaxIndexLength(t *testing.T) {
 	tk.MustExec("create table t (c1 varchar(3073), index(c1)) charset = ascii")
 	tk.MustExec(fmt.Sprintf("create table t1 (c1 varchar(%d), index(c1)) charset = ascii;", config.DefMaxOfMaxIndexLength))
 	err := tk.ExecToErr(fmt.Sprintf("create table t2 (c1 varchar(%d), index(c1)) charset = ascii;", config.DefMaxOfMaxIndexLength+1))
-	require.EqualError(t, err, "[ddl:1071]Specified key was too long; max key length is 12288 bytes")
+	require.EqualError(t, err, "[ddl:1071]Specified key was too long (12289 bytes); max key length is 12288 bytes")
 }
 
 func TestCreateTableWithLike(t *testing.T) {
diff --git a/errno/errname.go b/errno/errname.go
index 39deb486ff2fb..0f6c3db0e1645 100644
--- a/errno/errname.go
+++ b/errno/errname.go
@@ -92,7 +92,7 @@ var MySQLErrName = map[uint16]*mysql.ErrMessage{
 	ErrMultiplePriKey:                           mysql.Message("Multiple primary key defined", nil),
 	ErrTooManyKeys:                              mysql.Message("Too many keys specified; max %d keys allowed", nil),
 	ErrTooManyKeyParts:                          mysql.Message("Too many key parts specified; max %d parts allowed", nil),
-	ErrTooLongKey:                               mysql.Message("Specified key was too long; max key length is %d bytes", nil),
+	ErrTooLongKey:                               mysql.Message("Specified key was too long (%d bytes); max key length is %d bytes", nil),
 	ErrKeyColumnDoesNotExits:                    mysql.Message("Key column '%-.192s' doesn't exist in table", nil),
 	ErrBlobUsedAsKey:                            mysql.Message("BLOB column '%-.192s' can't be used in key specification with the used table type", nil),
 	ErrTooBigFieldlength:                        mysql.Message("Column length too big for column '%-.192s' (max = %d); use BLOB or TEXT instead", nil),
diff --git a/errors.toml b/errors.toml
index d7808c34337a1..9b503c113a836 100644
--- a/errors.toml
+++ b/errors.toml
@@ -668,7 +668,7 @@ Too many keys specified; max %d keys allowed
 
 ["ddl:1071"]
 error = '''
-Specified key was too long; max key length is %d bytes
+Specified key was too long (%d bytes); max key length is %d bytes
 '''
 
 ["ddl:1072"]
diff --git a/parser/mysql/errname.go b/parser/mysql/errname.go
index 3066d9f6fb6b0..5b1cff580f658 100644
--- a/parser/mysql/errname.go
+++ b/parser/mysql/errname.go
@@ -97,7 +97,7 @@ var MySQLErrName = map[uint16]*ErrMessage{
 	ErrMultiplePriKey:                           Message("Multiple primary key defined", nil),
 	ErrTooManyKeys:                              Message("Too many keys specified; max %d keys allowed", nil),
 	ErrTooManyKeyParts:                          Message("Too many key parts specified; max %d parts allowed", nil),
-	ErrTooLongKey:                               Message("Specified key was too long; max key length is %d bytes", nil),
+	ErrTooLongKey:                               Message("Specified key was too long (%d bytes); max key length is %d bytes", nil),
 	ErrKeyColumnDoesNotExits:                    Message("Key column '%-.192s' doesn't exist in table", nil),
 	ErrBlobUsedAsKey:                            Message("BLOB column '%-.192s' can't be used in key specification with the used table type", nil),
 	ErrTooBigFieldlength:                        Message("Column length too big for column '%-.192s' (max = %d); use BLOB or TEXT instead", nil),