diff --git a/internal/s3select/csv/record.go b/internal/s3select/csv/record.go
index c0dacc6c2..18e467834 100644
--- a/internal/s3select/csv/record.go
+++ b/internal/s3select/csv/record.go
@@ -125,9 +125,11 @@ func (r *Record) WriteCSV(writer io.Writer, opts sql.WriteCSVOpts) error {
 
 // WriteJSON - encodes to JSON data.
 func (r *Record) WriteJSON(writer io.Writer) error {
-	var kvs jstream.KVS = make([]jstream.KV, len(r.columnNames))
-	for i := 0; i < len(r.columnNames); i++ {
-		kvs[i] = jstream.KV{Key: r.columnNames[i], Value: r.csvRecord[i]}
+	var kvs jstream.KVS = make([]jstream.KV, 0, len(r.columnNames))
+	for i, cn := range r.columnNames {
+		if i < len(r.csvRecord) {
+			kvs = append(kvs, jstream.KV{Key: cn, Value: r.csvRecord[i]})
+		}
 	}
 	return json.NewEncoder(writer).Encode(kvs)
 }
diff --git a/internal/s3select/select_test.go b/internal/s3select/select_test.go
index d8cd85e32..3f2df9ce9 100644
--- a/internal/s3select/select_test.go
+++ b/internal/s3select/select_test.go
@@ -1547,6 +1547,36 @@ func TestCSVRanges(t *testing.T) {
         <Enabled>FALSE</Enabled>
     </RequestProgress>
 	<ScanRange></ScanRange>
+</SelectObjectContentRequest>`),
+		},
+		{
+			name: "var-field-count",
+			input: []byte(`id,time,num,num2,text
+1,2010-01-01T,7867786,4565.908123
+2,2017-01-02T03:04Z,-5, 0.765111,Some some
+`),
+			// Since we are doing offset, no headers are used.
+			wantResult: `{"id":"1","time":"2010-01-01T","num":"7867786","num2":"4565.908123"}
+{"id":"2","time":"2017-01-02T03:04Z","num":"-5","num2":" 0.765111","text":"Some some"}`,
+			wantErr: false,
+			requestXML: []byte(`<?xml version="1.0" encoding="UTF-8"?>
+<SelectObjectContentRequest>
+    <Expression>SELECT * from s3object</Expression>
+    <ExpressionType>SQL</ExpressionType>
+    <InputSerialization>
+        <CompressionType>NONE</CompressionType>
+        <CSV>
+        <FileHeaderInfo>USE</FileHeaderInfo>
+	    <QuoteCharacter>"</QuoteCharacter>
+        </CSV>
+    </InputSerialization>
+    <OutputSerialization>
+        <JSON>
+        </JSON>
+    </OutputSerialization>
+    <RequestProgress>
+        <Enabled>FALSE</Enabled>
+    </RequestProgress>
 </SelectObjectContentRequest>`),
 		},
 		{