diff --git a/schema.graphqls b/schema.graphqls
index c97987c..4e3c22d 100644
--- a/schema.graphqls
+++ b/schema.graphqls
@@ -10,7 +10,7 @@ type System {
 
   # TODO: Implement these in system resolvers
   parkingStructures: [ParkingStructure!]
-  parkingStructure(id: ID): ParkingStructure!
+  parkingStructure(id: ID): ParkingStructure
 }
 
 type ParkingStructure {
diff --git a/src/resolvers/SystemResolvers.ts b/src/resolvers/SystemResolvers.ts
index de8e3b0..4f5205f 100644
--- a/src/resolvers/SystemResolvers.ts
+++ b/src/resolvers/SystemResolvers.ts
@@ -70,13 +70,19 @@ export const SystemResolvers: Resolvers<ServerContext> = {
 
       return shuttle;
     },
-    shuttles: async (parent, args, contextValue, _info) => {
+    shuttles: async (parent, _args, contextValue, _info) => {
       const system = contextValue.findSystemById(parent.id);
       if (!system) {
         return [];
       }
 
       return await system.shuttleRepository.getShuttles();
-    }
+    },
+    parkingStructures: async (_parent, _args, _contextValue, _info) => {
+      return [];
+    },
+    parkingStructure: async (_parent, _args, _contextValue, _info) => {
+      return null;
+    },
   },
 }