diff --git a/beast/module/core/memory/MemoryBlock.h b/beast/module/core/memory/MemoryBlock.h
index 4364e2213a..fe002e9105 100644
--- a/beast/module/core/memory/MemoryBlock.h
+++ b/beast/module/core/memory/MemoryBlock.h
@@ -24,7 +24,9 @@
 #ifndef BEAST_MEMORYBLOCK_H_INCLUDED
 #define BEAST_MEMORYBLOCK_H_INCLUDED
 
+#include <beast/HeapBlock.h>
 #include <beast/utility/LeakChecked.h>
+#include <beast/strings/String.h>
 
 namespace beast {
 
diff --git a/beast/module/core/thread/Workers.h b/beast/module/core/thread/Workers.h
index 4bcf55e2a8..8ae56fe13f 100644
--- a/beast/module/core/thread/Workers.h
+++ b/beast/module/core/thread/Workers.h
@@ -21,6 +21,7 @@
 #define BEAST_WORKERS_H_INCLUDED
 
 #include <beast/module/core/system/SystemStats.h>
+#include <beast/threads/Thread.h>
 #include <beast/threads/semaphore.h>
 
 namespace beast {