diff --git a/context.go b/context.go
index 719ff8e..786ef74 100644
--- a/context.go
+++ b/context.go
@@ -128,7 +128,7 @@ func (c Context) ResultTime(value time.Time, format TimeFormat) {
 }
 
 func (c Context) resultRFC3339Nano(value time.Time) {
-	const maxlen = uint64(len(time.RFC3339Nano))
+	const maxlen = uint64(len(time.RFC3339Nano)) + 5
 
 	ptr := c.new(maxlen)
 	buf := util.View(c.mod, ptr, maxlen)
diff --git a/json.go b/json.go
index 1bd7a83..0dcdba0 100644
--- a/json.go
+++ b/json.go
@@ -5,6 +5,8 @@ import (
 	"strconv"
 	"time"
 	"unsafe"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 // JSON returns:
@@ -29,8 +31,7 @@ func (j jsonValue) UnmarshalJSON(data []byte) error {
 }
 
 func (j jsonValue) Scan(value any) error {
-	var mem [40]byte
-	buf := mem[:0]
+	var buf []byte
 
 	switch v := value.(type) {
 	case []byte:
@@ -47,6 +48,8 @@ func (j jsonValue) Scan(value any) error {
 		buf = append(buf, '"')
 	case nil:
 		buf = append(buf, "null"...)
+	default:
+		panic(util.AssertErr())
 	}
 
 	return j.UnmarshalJSON(buf)
diff --git a/stmt.go b/stmt.go
index 34b638a..04a91ec 100644
--- a/stmt.go
+++ b/stmt.go
@@ -237,7 +237,7 @@ func (s *Stmt) BindTime(param int, value time.Time, format TimeFormat) error {
 }
 
 func (s *Stmt) bindRFC3339Nano(param int, value time.Time) error {
-	const maxlen = uint64(len(time.RFC3339Nano))
+	const maxlen = uint64(len(time.RFC3339Nano)) + 5
 
 	ptr := s.c.new(maxlen)
 	buf := util.View(s.c.mod, ptr, maxlen)
@@ -430,8 +430,10 @@ func (s *Stmt) ColumnJSON(col int, ptr any) error {
 	var data []byte
 	switch s.ColumnType(col) {
 	case NULL:
-		data = []byte("null")
-	case TEXT, BLOB:
+		data = append(data, "null"...)
+	case TEXT:
+		data = s.ColumnRawText(col)
+	case BLOB:
 		data = s.ColumnRawBlob(col)
 	case INTEGER:
 		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
diff --git a/value.go b/value.go
index 6db8d15..0fcc5ef 100644
--- a/value.go
+++ b/value.go
@@ -132,8 +132,10 @@ func (v Value) JSON(ptr any) error {
 	var data []byte
 	switch v.Type() {
 	case NULL:
-		data = []byte("null")
-	case TEXT, BLOB:
+		data = append(data, "null"...)
+	case TEXT:
+		data = v.RawText()
+	case BLOB:
 		data = v.RawBlob()
 	case INTEGER:
 		data = strconv.AppendInt(nil, v.Int64(), 10)