diff --git a/csharp/ql/test/utils/model-generator/NoSummaries.cs b/csharp/ql/test/utils/model-generator/NoSummaries.cs
index 5d1f26574b0..112857f504e 100644
--- a/csharp/ql/test/utils/model-generator/NoSummaries.cs
+++ b/csharp/ql/test/utils/model-generator/NoSummaries.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace NoSummaries;
 
@@ -110,4 +111,24 @@ public abstract class BaseClass
 
     // Negative summary.
     public abstract string M2(string s);
+}
+
+// No methods in this class will have generated flow as
+// the simple types used in the collection are not bulk data types.
+public class CollectionFlow
+{
+    public int[] ReturnSimpleTypeArray(int[] a)
+    {
+        return a;
+    }
+
+    public List<int> ReturnSimpleTypeList(List<int> a)
+    {
+        return a;
+    }
+
+    public Dictionary<int, int> ReturnSimpleTypeDictionary(Dictionary<int, int> a)
+    {
+        return a;
+    }
 }
\ No newline at end of file
diff --git a/csharp/ql/test/utils/model-generator/Summaries.cs b/csharp/ql/test/utils/model-generator/Summaries.cs
index fe82980db9c..28e777700f2 100644
--- a/csharp/ql/test/utils/model-generator/Summaries.cs
+++ b/csharp/ql/test/utils/model-generator/Summaries.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Linq;
+using System.Collections;
 using System.Collections.Generic;
 
 namespace Summaries;
@@ -85,6 +86,31 @@ public class CollectionFlow
     {
         return new List<string> { tainted };
     }
+
+    public string[] ReturnComplexTypeArray(string[] a)
+    {
+        return a;
+    }
+
+    public List<byte> ReturnBulkTypeList(List<byte> a)
+    {
+        return a;
+    }
+
+    public Dictionary<int, string> ReturnComplexTypeDictionary(Dictionary<int, string> a)
+    {
+        return a;
+    }
+
+    public Array ReturnUntypedArray(Array a)
+    {
+        return a;
+    }
+
+    public IList ReturnUntypedList(IList a)
+    {
+        return a;
+    }
 }
 
 public class IEnumerableFlow