diff --git a/src/DIT.Workflower.DependencyInjection/DefaultWorkflowFactory.cs b/src/DIT.Workflower.DependencyInjection/DefaultWorkflowFactory.cs
index 65a338c..0711781 100644
--- a/src/DIT.Workflower.DependencyInjection/DefaultWorkflowFactory.cs
+++ b/src/DIT.Workflower.DependencyInjection/DefaultWorkflowFactory.cs
@@ -25,7 +25,7 @@ public class DefaultWorkflowFactory<TState, TCommand, TContext> : IWorkflowFacto
             .FirstOrDefault(x => x.Reference == reference);
 
         if (service is null)
-            throw new ArgumentOutOfRangeException(nameof(version), $"Workflow reference {id}.v{version} does not exist");
+            throw new KeyNotFoundException($"Workflow reference {id}.v{version} does not exist");
 
         return service;
     }
diff --git a/tests/DIT.Workflower.Tests/DependencyInjection/DependencyInjectionTests.cs b/tests/DIT.Workflower.Tests/DependencyInjection/DependencyInjectionTests.cs
index b5649c8..f06cd4b 100644
--- a/tests/DIT.Workflower.Tests/DependencyInjection/DependencyInjectionTests.cs
+++ b/tests/DIT.Workflower.Tests/DependencyInjection/DependencyInjectionTests.cs
@@ -75,4 +75,19 @@ public class DependencyInjectionTests
         Assert.Equal("PhoneState_PhoneCommand_PhoneCall", workflow.Id);
     }
 
+    [Fact]
+    public void UnknownWorkflowReferenceThrows()
+    {
+        var sc = new ServiceCollection();
+
+        sc.AddWorkflowDefinition<PhoneState, PhoneCommand, PhoneCall>(version: 1)
+            .From(PhoneState.Idle)
+                .On(PhoneCommand.IncomingCall)
+                .To(PhoneState.Ringing);
+
+        var sp = sc.BuildServiceProvider();
+        var workflowFactory = sp.GetRequiredService<IWorkflowFactory<PhoneState, PhoneCommand, PhoneCall>>();
+        Assert.Throws<KeyNotFoundException>(() => workflowFactory.CreateWorkflow("unknown"));
+    }
+
 }