diff --git a/src/Reactor/ReactorUnitTests.cpp b/src/Reactor/ReactorUnitTests.cpp
index 584bd8b..dcfe961 100644
--- a/src/Reactor/ReactorUnitTests.cpp
+++ b/src/Reactor/ReactorUnitTests.cpp
@@ -1732,6 +1732,44 @@
 	EXPECT_EQ(out, 99);
 }
 
+TEST(ReactorUnitTests, ExtractFromRValue)
+{
+	Function<Void(Pointer<Int4> values, Pointer<Int4> result)> function;
+	{
+		Pointer<Int4> vIn = function.Arg<0>();
+		Pointer<Int4> resultIn = function.Arg<1>();
+
+		RValue<Int4> v = *vIn;
+
+		Int4 result(678);
+
+		If(Extract(v, 0) == 42)
+		{
+			result = Insert(result, 1, 0);
+		}
+
+		If(Extract(v, 1) == 42)
+		{
+			result = Insert(result, 1, 1);
+		}
+
+		*resultIn = result;
+
+		Return();
+	}
+
+	auto routine = function("one");
+	auto entry = (void(*)(int*, int*))routine->getEntry();
+
+	int v[4] = { 42, 42, 42, 42 };
+	int result[4] = { 99, 99, 99, 99 };
+	entry(v, result);
+	EXPECT_EQ(result[0], 1);
+	EXPECT_EQ(result[1], 1);
+	EXPECT_EQ(result[2], 678);
+	EXPECT_EQ(result[3], 678);
+}
+
 int main(int argc, char **argv)
 {
 	::testing::InitGoogleTest(&argc, argv);
diff --git a/src/Reactor/SubzeroReactor.cpp b/src/Reactor/SubzeroReactor.cpp
index 1c94c5e..1ec7404 100644
--- a/src/Reactor/SubzeroReactor.cpp
+++ b/src/Reactor/SubzeroReactor.cpp
@@ -652,6 +652,9 @@
 
 		rr::optimize(::function);
 
+		::function->computeInOutEdges();
+		ASSERT(!::function->hasError());
+
 		::function->translate();
 		ASSERT(!::function->hasError());