diff --git a/db/queries/queries.sql b/db/queries/queries.sql
index 9584c8a..6a6257b 100644
--- a/db/queries/queries.sql
+++ b/db/queries/queries.sql
@@ -222,8 +222,8 @@ LEFT JOIN LATERAL (
 ) po ON true
 LEFT JOIN observers o ON o.id = po.observer_id
 WHERE
-  ($1 = 0 OR p.payload_type = $1)
-  AND ($2 = 0 OR p.route_type = $2)
+  ($1::smallint = -1 OR p.payload_type = $1::smallint)
+  AND ($2::smallint = -1 OR p.route_type = $2::smallint)
   AND ($3 = '' OR po.iata ILIKE $3)
   AND ($4::timestamptz IS NULL OR p.first_heard_at >= $4)
   AND ($5::timestamptz IS NULL OR p.first_heard_at <= $5)
diff --git a/db/sqlc/queries.sql.go b/db/sqlc/queries.sql.go
index d2ec3cf..422504c 100644
--- a/db/sqlc/queries.sql.go
+++ b/db/sqlc/queries.sql.go
@@ -1777,8 +1777,8 @@ LEFT JOIN LATERAL (
 ) po ON true
 LEFT JOIN observers o ON o.id = po.observer_id
 WHERE
-  ($1 = 0 OR p.payload_type = $1)
-  AND ($2 = 0 OR p.route_type = $2)
+  ($1::smallint = -1 OR p.payload_type = $1::smallint)
+  AND ($2::smallint = -1 OR p.route_type = $2::smallint)
   AND ($3 = '' OR po.iata ILIKE $3)
   AND ($4::timestamptz IS NULL OR p.first_heard_at >= $4)
   AND ($5::timestamptz IS NULL OR p.first_heard_at <= $5)
@@ -1788,8 +1788,8 @@ LIMIT $7
 `
 
 type ListPacketsParams struct {
-	Column1 interface{}        `json:"column_1"`
-	Column2 interface{}        `json:"column_2"`
+	Column1 int16              `json:"column_1"`
+	Column2 int16              `json:"column_2"`
 	Column3 interface{}        `json:"column_3"`
 	Column4 pgtype.Timestamptz `json:"column_4"`
 	Column5 pgtype.Timestamptz `json:"column_5"`
diff --git a/internal/api/handlers/packets.go b/internal/api/handlers/packets.go
index c19c7d3..5f8673a 100644
--- a/internal/api/handlers/packets.go
+++ b/internal/api/handlers/packets.go
@@ -40,7 +40,7 @@ func PacketsRouter(reader api.Reader) http.Handler {
 //	@Router		/packets [get]
 func listPackets(reader api.Reader) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		var payloadType int16
+		var payloadType int16 = -1
 		if p := r.URL.Query().Get("payloadType"); p != "" {
 			t, err := strconv.ParseInt(p, 10, 16)
 			if err != nil {
@@ -49,12 +49,12 @@ func listPackets(reader api.Reader) http.HandlerFunc {
 			}
 			payloadType = int16(t)
 		}
-		if payloadType == 0 {
+		if payloadType == -1 {
 			if p := r.URL.Query().Get("payloadTypeName"); p != "" {
 				payloadType = api.PayloadTypeFromString(p)
 			}
 		}
-		var routeType int16
+		var routeType int16 = -1
 		if p := r.URL.Query().Get("routeType"); p != "" {
 			t, err := strconv.ParseInt(p, 10, 16)
 			if err != nil {
diff --git a/internal/api/helpers.go b/internal/api/helpers.go
index 54ecc85..d291d8c 100644
--- a/internal/api/helpers.go
+++ b/internal/api/helpers.go
@@ -47,7 +47,7 @@ func PayloadTypeName(t int16) string {
 }
 
 // PayloadTypeFromString returns the integer payload type for a given name.
-// Returns 0 (no filter) if the string is empty or unrecognized.
+// Returns -1 (no filter) if the string is empty or unrecognized.
 func PayloadTypeFromString(s string) int16 {
 	switch strings.ToLower(s) {
 	case "request", "req":
@@ -77,7 +77,7 @@ func PayloadTypeFromString(s string) int16 {
 	case "raw_custom", "raw", "custom":
 		return int16(meshcore.PayloadTypeRawCustom)
 	default:
-		return 0
+		return -1
 	}
 }