diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index 5640716a766ff..09676d993eebe 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -906,9 +906,13 @@ Type TypeBase::lookThroughAllOptionalTypes(SmallVectorImpl<Type> &optionals){
 }
 
 unsigned int TypeBase::getOptionalityDepth() {
-  SmallVector<Type> types;
-  lookThroughAllOptionalTypes(types);
-  return types.size();
+  Type type(this);
+  unsigned int depth = 0;
+  while (auto objType = type->getOptionalObjectType()) {
+    type = objType;
+    ++depth;
+  }
+  return depth;
 }
 
 Type TypeBase::stripConcurrency(bool recurse, bool dropGlobalActor) {