diff --git a/Source/Tools/Flax.Build/ProjectInfo.cs b/Source/Tools/Flax.Build/ProjectInfo.cs
index c64627e3c..2c3a600dd 100644
--- a/Source/Tools/Flax.Build/ProjectInfo.cs
+++ b/Source/Tools/Flax.Build/ProjectInfo.cs
@@ -260,7 +260,11 @@ namespace Flax.Build
                 return true;
             var rules = Builder.GenerateRulesAssembly();
             var target = rules.GetTarget(name);
-            return target == null || target.Modules.TrueForAll(x => !rules.GetModule(x).BuildNativeCode);
+            return target == null || target.Modules.TrueForAll(moduleName =>
+            {
+                var module = rules.GetModule(moduleName);
+                return module != null && !module.BuildNativeCode;
+            });
         }
 
         /// <summary>