diff --git a/csharp/ql/test/library-tests/obinit/Flow.expected b/csharp/ql/test/library-tests/obinit/Flow.expected
new file mode 100644
index 00000000000..dea9d8df930
--- /dev/null
+++ b/csharp/ql/test/library-tests/obinit/Flow.expected
@@ -0,0 +1,18 @@
+edges
+| obinit.cs:5:23:5:23 | [post] this access : A [field s] : String | obinit.cs:7:16:7:16 | this [Return] : A [field s] : String | provenance |  |
+| obinit.cs:5:27:5:34 | "source" : String | obinit.cs:5:23:5:23 | [post] this access : A [field s] : String | provenance |  |
+| obinit.cs:7:16:7:16 | this [Return] : A [field s] : String | obinit.cs:20:19:20:25 | object creation of type A : A [field s] : String | provenance |  |
+| obinit.cs:20:15:20:15 | access to local variable a : A [field s] : String | obinit.cs:21:18:21:18 | access to local variable a : A [field s] : String | provenance |  |
+| obinit.cs:20:19:20:25 | object creation of type A : A [field s] : String | obinit.cs:20:15:20:15 | access to local variable a : A [field s] : String | provenance |  |
+| obinit.cs:21:18:21:18 | access to local variable a : A [field s] : String | obinit.cs:21:18:21:20 | access to field s | provenance |  |
+nodes
+| obinit.cs:5:23:5:23 | [post] this access : A [field s] : String | semmle.label | [post] this access : A [field s] : String |
+| obinit.cs:5:27:5:34 | "source" : String | semmle.label | "source" : String |
+| obinit.cs:7:16:7:16 | this [Return] : A [field s] : String | semmle.label | this [Return] : A [field s] : String |
+| obinit.cs:20:15:20:15 | access to local variable a : A [field s] : String | semmle.label | access to local variable a : A [field s] : String |
+| obinit.cs:20:19:20:25 | object creation of type A : A [field s] : String | semmle.label | object creation of type A : A [field s] : String |
+| obinit.cs:21:18:21:18 | access to local variable a : A [field s] : String | semmle.label | access to local variable a : A [field s] : String |
+| obinit.cs:21:18:21:20 | access to field s | semmle.label | access to field s |
+subpaths
+#select
+| obinit.cs:21:18:21:20 | access to field s |
diff --git a/csharp/ql/test/library-tests/obinit/Flow.ql b/csharp/ql/test/library-tests/obinit/Flow.ql
new file mode 100644
index 00000000000..93c4bd24e5a
--- /dev/null
+++ b/csharp/ql/test/library-tests/obinit/Flow.ql
@@ -0,0 +1,22 @@
+import csharp
+
+module FlowConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) {
+    source.asExpr().(StringLiteral).getValue() = "source"
+  }
+
+  predicate isSink(DataFlow::Node sink) {
+    exists(MethodCall mc |
+      mc.getTarget().getUndecoratedName() = "Sink" and
+      mc.getAnArgument() = sink.asExpr()
+    )
+  }
+}
+
+module Flow = DataFlow::Global<FlowConfig>;
+
+import Flow::PathGraph
+
+from DataFlow::Node source, DataFlow::Node sink
+where Flow::flow(source, sink)
+select sink
diff --git a/csharp/ql/test/library-tests/obinit/obinit.cs b/csharp/ql/test/library-tests/obinit/obinit.cs
new file mode 100644
index 00000000000..e4e851ed1d8
--- /dev/null
+++ b/csharp/ql/test/library-tests/obinit/obinit.cs
@@ -0,0 +1,30 @@
+namespace ObInit {
+    public class A {
+        int x = 1;
+
+        public string s = "source";
+
+        public A() { }
+
+        public A(int y) { }
+
+        public A(int y, int z) : this(y) { }
+    }
+
+    public class B : A {
+        public B() : base(10) { }
+
+        static void Sink(string s) { }
+
+        static void Foo() {
+            A a = new A();
+            Sink(a.s);
+
+            A a2 = new A(0, 0);
+            Sink(a2.s);
+
+            B b = new B();
+            Sink(b.s);
+        }
+    }
+}