diff --git a/server/shared/types/index.ts b/server/shared/types/index.ts
index f9a471e..4db8440 100644
--- a/server/shared/types/index.ts
+++ b/server/shared/types/index.ts
@@ -699,7 +699,13 @@ export type NodesFilter = {
     onlineState?: OnlineState;
 };
 
-export const NODES_FILTER_FIELDS = {
+export const NODES_FILTER_FIELDS: Record<
+    keyof NodesFilter,
+    | BooleanConstructor
+    | StringConstructor
+    | typeof MonitoringState
+    | typeof OnlineState
+> = {
     hasKey: Boolean,
     hasCoords: Boolean,
     monitoringState: MonitoringState,