diff --git a/src/mem/cache/cache_blk.hh b/src/mem/cache/cache_blk.hh
index 67e65d25bb..a75c9611de 100644
--- a/src/mem/cache/cache_blk.hh
+++ b/src/mem/cache/cache_blk.hh
@@ -38,6 +38,8 @@
 #include "sim/root.hh"		// for Tick
 #include "arch/isa_traits.hh"	// for Addr
 
+#include <iostream>
+
 /**
  * Cache block status bit assignments
  */