diff --git a/base/allocator/partition_allocator/partition_alloc.h b/base/allocator/partition_allocator/partition_alloc.h
index 549451e2d..17b7deab3 100644
--- a/base/allocator/partition_allocator/partition_alloc.h
+++ b/base/allocator/partition_allocator/partition_alloc.h
@@ -582,7 +582,7 @@ struct BASE_EXPORT PartitionRoot {
       EXCLUSIVE_LOCKS_REQUIRED(lock_);
   void DecommitEmptyPages() EXCLUSIVE_LOCKS_REQUIRED(lock_);
 
-  friend class internal::ThreadCache;
+  friend class base::internal::ThreadCache;
 };
 
 static_assert(sizeof(PartitionRoot<internal::ThreadSafe>) ==
diff --git a/base/allocator/partition_allocator/thread_cache.h b/base/allocator/partition_allocator/thread_cache.h
index dd71ccc09..05097470a 100644
--- a/base/allocator/partition_allocator/thread_cache.h
+++ b/base/allocator/partition_allocator/thread_cache.h
@@ -5,6 +5,7 @@
 #ifndef BASE_ALLOCATOR_PARTITION_ALLOCATOR_THREAD_CACHE_H_
 #define BASE_ALLOCATOR_PARTITION_ALLOCATOR_THREAD_CACHE_H_
 
+#include <atomic>
 #include <cstdint>
 #include <memory>