diff --git a/lldb/include/lldb/Utility/SharedCluster.h b/lldb/include/lldb/Utility/SharedCluster.h
--- a/lldb/include/lldb/Utility/SharedCluster.h
+++ b/lldb/include/lldb/Utility/SharedCluster.h
@@ -11,7 +11,7 @@
 
 #include "lldb/Utility/LLDBAssert.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
 
 #include <memory>
 #include <mutex>
@@ -32,15 +32,15 @@
 
   void ManageObject(T *new_object) {
     std::lock_guard<std::mutex> guard(m_mutex);
-    assert(!llvm::is_contained(m_objects, new_object) &&
-           "ManageObject called twice for the same object?");
-    m_objects.push_back(new_object);
+    auto ret = m_objects.insert(new_object);
+    assert(ret.second && "ManageObject called twice for the same object?");
   }
 
   std::shared_ptr<T> GetSharedPointer(T *desired_object) {
     std::lock_guard<std::mutex> guard(m_mutex);
     auto this_sp = this->shared_from_this();
-    if (!llvm::is_contained(m_objects, desired_object)) {
+    size_t count =  m_objects.count(desired_object);
+    if (count == 0) {
       lldbassert(false && "object not found in shared cluster when expected");
       desired_object = nullptr;
     }
@@ -49,8 +49,7 @@
 
 private:
   ClusterManager() : m_objects() {}
-
-  llvm::SmallVector<T *, 16> m_objects;
+  llvm::SmallPtrSet<T *, 16> m_objects;
   std::mutex m_mutex;
 };