diff --git a/ioengine.h b/ioengine.h
index 9392bbd..b4bc22b 100644
--- a/ioengine.h
+++ b/ioengine.h
@@ -1,7 +1,10 @@
 #ifndef FIO_IOENGINE_H
 #define FIO_IOENGINE_H
 
+#include "compiler/compiler.h"
+#include "io_ddir.h"
 #include "debug.h"
+#include "file.h"
 
 #define FIO_IOOPS_VERSION	13
 
@@ -16,6 +19,8 @@
 	IO_U_F_VER_LIST		= 1 << 7,
 };
 
+struct thread_data;
+
 /*
  * The io unit
  */