diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 48513bb32..49197408e 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -3174,6 +3174,7 @@ class WidthVisitor final : public VNVisitor {
                                              << nodep->fromp()->prettyTypeName()
                                              << "' which is a '"
                                              << nodep->fromp()->dtypep()->prettyTypeName() << "'");
+            nodep->dtypep(m_vup->dtypeNullp());
         }
     }
     AstWith* methodWithArgument(AstNodeFTaskRef* nodep, bool required, bool arbReturn,