diff --git a/stdlib/public/runtime/Demangle.cpp b/stdlib/public/runtime/Demangle.cpp
index 4d8f8ce..8f38a52 100644
--- a/stdlib/public/runtime/Demangle.cpp
+++ b/stdlib/public/runtime/Demangle.cpp
@@ -87,8 +87,8 @@
       auto extension = llvm::cast<ExtensionContextDescriptor>(component);
       // Demangle the extension self type.
       auto selfType = Dem.demangleType(extension->getMangledExtendedContext());
-      assert(selfType->getKind() == Node::Kind::Type);
-      selfType = selfType->getChild(0);
+      if (selfType->getKind() == Node::Kind::Type)
+        selfType = selfType->getChild(0);
       
       // Substitute in the generic arguments.
       // TODO: This kludge only kinda works if there are no same-type