diff --git a/Content.Server/GameObjects/EntitySystems/ConstructionSystem.cs b/Content.Server/GameObjects/EntitySystems/ConstructionSystem.cs
index 96520441b8..f415bf2b98 100644
--- a/Content.Server/GameObjects/EntitySystems/ConstructionSystem.cs
+++ b/Content.Server/GameObjects/EntitySystems/ConstructionSystem.cs
@@ -20,6 +20,7 @@ using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Random;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
@@ -306,8 +307,18 @@ namespace Content.Server.GameObjects.EntitySystems
 
         private async void HandleStartItemConstruction(TryStartItemConstructionMessage ev, EntitySessionEventArgs args)
         {
-            var constructionPrototype = _prototypeManager.Index<ConstructionPrototype>(ev.PrototypeName);
-            var constructionGraph = _prototypeManager.Index<ConstructionGraphPrototype>(constructionPrototype.Graph);
+            if (!_prototypeManager.TryIndex(ev.PrototypeName, out ConstructionPrototype constructionPrototype))
+            {
+                Logger.Error($"Tried to start construction of invalid recipe '{ev.PrototypeName}'!");
+                return;
+            }
+
+            if (!_prototypeManager.TryIndex(constructionPrototype.Graph, out ConstructionGraphPrototype constructionGraph))
+            {
+                Logger.Error($"Invalid construction graph '{constructionPrototype.Graph}' in recipe '{ev.PrototypeName}'!");
+                return;
+            }
+
             var startNode = constructionGraph.Nodes[constructionPrototype.StartNode];
             var targetNode = constructionGraph.Nodes[constructionPrototype.TargetNode];
             var pathFind = constructionGraph.Path(startNode.Name, targetNode.Name);
@@ -352,8 +363,20 @@ namespace Content.Server.GameObjects.EntitySystems
 
         private async void HandleStartStructureConstruction(TryStartStructureConstructionMessage ev, EntitySessionEventArgs args)
         {
-            var constructionPrototype = _prototypeManager.Index<ConstructionPrototype>(ev.PrototypeName);
-            var constructionGraph = _prototypeManager.Index<ConstructionGraphPrototype>(constructionPrototype.Graph);
+            if (!_prototypeManager.TryIndex(ev.PrototypeName, out ConstructionPrototype constructionPrototype))
+            {
+                Logger.Error($"Tried to start construction of invalid recipe '{ev.PrototypeName}'!");
+                RaiseNetworkEvent(new AckStructureConstructionMessage(ev.Ack));
+                return;
+            }
+
+            if (!_prototypeManager.TryIndex(constructionPrototype.Graph, out ConstructionGraphPrototype constructionGraph))
+            {
+                Logger.Error($"Invalid construction graph '{constructionPrototype.Graph}' in recipe '{ev.PrototypeName}'!");
+                RaiseNetworkEvent(new AckStructureConstructionMessage(ev.Ack));
+                return;
+            }
+
             var startNode = constructionGraph.Nodes[constructionPrototype.StartNode];
             var targetNode = constructionGraph.Nodes[constructionPrototype.TargetNode];
             var pathFind = constructionGraph.Path(startNode.Name, targetNode.Name);