diff --git a/api/openapi/readers.yml b/api/openapi/readers.yml
index 420e8c4b0c2..ed8d3a96e31 100644
--- a/api/openapi/readers.yml
+++ b/api/openapi/readers.yml
@@ -244,10 +244,10 @@ components:
         type: string
         default: none
         enum:
-          - avg
-          - sum
-          - min
-          - max
+          - MAX
+          - SUM
+          - MIN
+          - MAX
       required: false
     Interval:
       name: interval
diff --git a/readers/timescale/messages.go b/readers/timescale/messages.go
index c9c6157f604..bc3d883e10d 100644
--- a/readers/timescale/messages.go
+++ b/readers/timescale/messages.go
@@ -31,7 +31,7 @@ func New(db *sqlx.DB) readers.MessageRepository {
 func (tr timescaleRepository) ReadAll(chanID string, rpm readers.PageMetadata) (readers.MessagesPage, error) {
 	order := "time"
 	format := defTable
-	baseQuery := fmt.Sprintf(`FROM %s WHERE %s GROUP BY time`, format, fmtCondition(rpm))
+	baseQuery := fmt.Sprintf(`FROM %s WHERE %s GROUP BY 1`, format, fmtCondition(rpm))
 
 	if rpm.Format != "" && rpm.Format != defTable {
 		order = "created"
@@ -42,7 +42,7 @@ func (tr timescaleRepository) ReadAll(chanID string, rpm readers.PageMetadata) (
 	// If aggregation is provided, add time_bucket and aggregation to the query
 	switch {
 	case rpm.Aggregation != "":
-		q = fmt.Sprintf(`SELECT EXTRACT(epoch FROM time_bucket('%s', to_timestamp(time/1000))) AS time, %s(value) AS value %s ORDER BY %s DESC LIMIT :limit OFFSET :offset;`, rpm.Interval, rpm.Aggregation, baseQuery, order)
+		q = fmt.Sprintf(`SELECT EXTRACT(epoch FROM time_bucket('%s', to_timestamp(time/1000))) AS time, %s(value) AS value %s ORDER BY 1 DESC LIMIT :limit OFFSET :offset;`, rpm.Interval, rpm.Aggregation, baseQuery)
 	default:
 		// Construct the base query without time_bucket and aggregation
 		q = fmt.Sprintf(`SELECT * FROM %s WHERE %s ORDER BY %s DESC LIMIT :limit OFFSET :offset;`, format, fmtCondition(rpm), order)