diff --git a/csharp/ql/test/library-tests/csharp7.3/PrintAst.expected b/csharp/ql/test/library-tests/csharp7.3/PrintAst.expected
index 29ad30dc223..b3fa3781436 100644
--- a/csharp/ql/test/library-tests/csharp7.3/PrintAst.expected
+++ b/csharp/ql/test/library-tests/csharp7.3/PrintAst.expected
@@ -75,8 +75,8 @@ csharp73.cs:
 #   22|           -1: [TypeMention] Span<int>
 #   22|             1: [TypeMention] int
 #   22|           0: [LocalVariableAccess] access to local variable t
-#   22|           1: [OperatorCall] call to operator implicit conversion
-#   22|             0: [ArrayCreation] array creation of type Int32[]
+#   22|           1: [CastExpr] (...) ...
+#   22|             1: [ArrayCreation] array creation of type Int32[]
 #   22|               -1: [TypeMention] Int32[]
 #   22|                 1: [TypeMention] int
 #   22|               0: [IntLiteral] 10
diff --git a/csharp/ql/test/library-tests/dataflow/local/DataFlowStep.expected b/csharp/ql/test/library-tests/dataflow/local/DataFlowStep.expected
index 16e0aa842c5..861e4c519a8 100644
--- a/csharp/ql/test/library-tests/dataflow/local/DataFlowStep.expected
+++ b/csharp/ql/test/library-tests/dataflow/local/DataFlowStep.expected
@@ -507,11 +507,11 @@
 | LocalDataFlow.cs:353:21:353:21 | access to parameter x | LocalDataFlow.cs:353:16:353:21 | ... = ... |
 | LocalDataFlow.cs:356:33:356:34 | access to parameter os | LocalDataFlow.cs:356:27:356:29 | access to local variable os2 |
 | LocalDataFlow.cs:356:33:356:34 | access to parameter os | LocalDataFlow.cs:356:27:356:34 | ... = ... |
-| LocalDataFlow.cs:361:41:361:44 | SSA param(args) | LocalDataFlow.cs:363:29:363:32 | access to parameter args |
+| LocalDataFlow.cs:361:41:361:44 | SSA param(args) | LocalDataFlow.cs:364:27:364:30 | access to parameter args |
 | LocalDataFlow.cs:361:41:361:44 | args | LocalDataFlow.cs:361:41:361:44 | SSA param(args) |
-| LocalDataFlow.cs:363:29:363:32 | [post] access to parameter args | LocalDataFlow.cs:364:27:364:30 | access to parameter args |
-| LocalDataFlow.cs:363:29:363:32 | access to parameter args | LocalDataFlow.cs:364:27:364:30 | access to parameter args |
-| LocalDataFlow.cs:363:29:363:32 | call to operator implicit conversion | LocalDataFlow.cs:363:22:363:25 | access to local variable span |
+| LocalDataFlow.cs:361:56:361:57 | SSA param(dt) | LocalDataFlow.cs:363:30:363:31 | access to parameter dt |
+| LocalDataFlow.cs:361:56:361:57 | dt | LocalDataFlow.cs:361:56:361:57 | SSA param(dt) |
+| LocalDataFlow.cs:363:30:363:31 | call to operator implicit conversion | LocalDataFlow.cs:363:24:363:26 | access to local variable dto |
 | LocalDataFlow.cs:364:27:364:30 | call to operator implicit conversion | LocalDataFlow.cs:364:23:364:23 | access to local variable x |
 | LocalDataFlow.cs:367:23:367:24 | SSA param(b1) | LocalDataFlow.cs:371:13:371:14 | access to parameter b1 |
 | LocalDataFlow.cs:367:23:367:24 | b1 | LocalDataFlow.cs:367:23:367:24 | SSA param(b1) |
diff --git a/csharp/ql/test/library-tests/dataflow/local/LocalDataFlow.cs b/csharp/ql/test/library-tests/dataflow/local/LocalDataFlow.cs
index 900a2161715..53b6165dd75 100644
--- a/csharp/ql/test/library-tests/dataflow/local/LocalDataFlow.cs
+++ b/csharp/ql/test/library-tests/dataflow/local/LocalDataFlow.cs
@@ -358,9 +358,9 @@ public class LocalDataFlow
 
     public static implicit operator LocalDataFlow(string[] args) => null;
 
-    public void ConversionFlow(string[] args)
+    public void ConversionFlow(string[] args, DateTime dt)
     {
-        Span<object> span = args; // flow (library operator)
+        DateTimeOffset dto = dt; // flow (library operator)
         LocalDataFlow x = args; // no flow (source code operator)
     }
 
diff --git a/csharp/ql/test/library-tests/dataflow/local/TaintTrackingStep.expected b/csharp/ql/test/library-tests/dataflow/local/TaintTrackingStep.expected
index 2dc753a1889..b2d395d4b83 100644
--- a/csharp/ql/test/library-tests/dataflow/local/TaintTrackingStep.expected
+++ b/csharp/ql/test/library-tests/dataflow/local/TaintTrackingStep.expected
@@ -618,12 +618,12 @@
 | LocalDataFlow.cs:353:21:353:21 | access to parameter x | LocalDataFlow.cs:353:16:353:21 | ... = ... |
 | LocalDataFlow.cs:356:33:356:34 | access to parameter os | LocalDataFlow.cs:356:27:356:29 | access to local variable os2 |
 | LocalDataFlow.cs:356:33:356:34 | access to parameter os | LocalDataFlow.cs:356:27:356:34 | ... = ... |
-| LocalDataFlow.cs:361:41:361:44 | SSA param(args) | LocalDataFlow.cs:363:29:363:32 | access to parameter args |
+| LocalDataFlow.cs:361:41:361:44 | SSA param(args) | LocalDataFlow.cs:364:27:364:30 | access to parameter args |
 | LocalDataFlow.cs:361:41:361:44 | args | LocalDataFlow.cs:361:41:361:44 | SSA param(args) |
-| LocalDataFlow.cs:363:29:363:32 | [post] access to parameter args | LocalDataFlow.cs:364:27:364:30 | access to parameter args |
-| LocalDataFlow.cs:363:29:363:32 | access to parameter args | LocalDataFlow.cs:363:29:363:32 | call to operator implicit conversion |
-| LocalDataFlow.cs:363:29:363:32 | access to parameter args | LocalDataFlow.cs:364:27:364:30 | access to parameter args |
-| LocalDataFlow.cs:363:29:363:32 | call to operator implicit conversion | LocalDataFlow.cs:363:22:363:25 | access to local variable span |
+| LocalDataFlow.cs:361:56:361:57 | SSA param(dt) | LocalDataFlow.cs:363:30:363:31 | access to parameter dt |
+| LocalDataFlow.cs:361:56:361:57 | dt | LocalDataFlow.cs:361:56:361:57 | SSA param(dt) |
+| LocalDataFlow.cs:363:30:363:31 | access to parameter dt | LocalDataFlow.cs:363:30:363:31 | call to operator implicit conversion |
+| LocalDataFlow.cs:363:30:363:31 | call to operator implicit conversion | LocalDataFlow.cs:363:24:363:26 | access to local variable dto |
 | LocalDataFlow.cs:364:27:364:30 | call to operator implicit conversion | LocalDataFlow.cs:364:23:364:23 | access to local variable x |
 | LocalDataFlow.cs:367:23:367:24 | SSA param(b1) | LocalDataFlow.cs:371:13:371:14 | access to parameter b1 |
 | LocalDataFlow.cs:367:23:367:24 | b1 | LocalDataFlow.cs:367:23:367:24 | SSA param(b1) |