diff --git a/protocol/client_query.go b/protocol/client_query.go
index a860056..26bfeec 100644
--- a/protocol/client_query.go
+++ b/protocol/client_query.go
@@ -2,9 +2,29 @@ package protocol
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 )
 
+var supportedClientQueryTypes = buildSupportedClientQueryTypes()
+
+func buildSupportedClientQueryTypes() []string {
+	typesList := []string{
+		"ATC", "CAPS", "C?",
+		"RN", "SV", "ATIS",
+		"IP", "INF", "FP",
+		"IPC", "BY", "HI",
+		"HLP", "NOHLP", "WH",
+		"IT", "HT", "DR",
+		"FA", "TA", "BC",
+		"SC", "VT", "ACC",
+		"NEWINFO", "NEWATIS", "EST",
+		"GD", "SIMDATA"}
+
+	slices.Sort(typesList)
+	return typesList
+}
+
 type ClientQueryPDU struct {
 	From      string `validate:"required,alphanum,max=16"`
 	To        string `validate:"required,max=7"`
@@ -49,18 +69,7 @@ func (p *ClientQueryPDU) Parse(packet string) error {
 		return err
 	}
 
-	switch pdu.QueryType {
-	case "ATC", "CAPS", "C?",
-		"RN", "SV", "ATIS",
-		"IP", "INF", "FP",
-		"IPC", "BY", "HI",
-		"HLP", "NOHLP", "WH",
-		"IT", "HT", "DR",
-		"FA", "TA", "BC",
-		"SC", "VT", "ACC",
-		"NEWINFO", "NEWATIS", "EST",
-		"GD":
-	default:
+	if _, exists := slices.BinarySearch(supportedClientQueryTypes, pdu.QueryType); !exists {
 		return NewGenericFSDError(SyntaxError, fields[2], "invalid query type")
 	}
 
diff --git a/protocol/client_query_response.go b/protocol/client_query_response.go
index 685f388..26888b2 100644
--- a/protocol/client_query_response.go
+++ b/protocol/client_query_response.go
@@ -2,6 +2,7 @@ package protocol
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 )
 
@@ -50,18 +51,7 @@ func (p *ClientQueryResponsePDU) Parse(packet string) error {
 		return err
 	}
 
-	switch pdu.QueryType {
-	case "ATC", "CAPS", "C?",
-		"RN", "SV", "ATIS",
-		"IP", "INF", "FP",
-		"IPC", "BY", "HI",
-		"HLP", "NOHLP", "WH",
-		"IT", "HT", "DR",
-		"FA", "TA", "BC",
-		"SC", "VT", "ACC",
-		"NEWINFO", "NEWATIS", "EST",
-		"GD":
-	default:
+	if _, exists := slices.BinarySearch(supportedClientQueryTypes, pdu.QueryType); !exists {
 		return NewGenericFSDError(SyntaxError, fields[2], "invalid query type")
 	}