diff --git a/src/mem/cache/tags/base.hh b/src/mem/cache/tags/base.hh
index 30da408558..9a9de8cfac 100644
--- a/src/mem/cache/tags/base.hh
+++ b/src/mem/cache/tags/base.hh
@@ -63,6 +63,7 @@
 #include "sim/clocked_object.hh"
 
 class BaseCache;
+class ReplaceableEntry;
 
 /**
  * A common base class of Cache tagstore objects.
diff --git a/src/mem/cache/tags/fa_lru.hh b/src/mem/cache/tags/fa_lru.hh
index dee1af0287..35413c2530 100644
--- a/src/mem/cache/tags/fa_lru.hh
+++ b/src/mem/cache/tags/fa_lru.hh
@@ -68,6 +68,8 @@
 // TrackedCaches class
 //#define FALRU_DEBUG
 
+class ReplaceableEntry;
+
 // A bitmask of the caches we are keeping track of. Currently the
 // lowest bit is the smallest cache we are tracking, as it is
 // specified by the corresponding parameter. The rest of the bits are
diff --git a/src/mem/cache/tags/sector_tags.hh b/src/mem/cache/tags/sector_tags.hh
index d0dc1f7e31..c0dae8dd43 100644
--- a/src/mem/cache/tags/sector_tags.hh
+++ b/src/mem/cache/tags/sector_tags.hh
@@ -45,6 +45,7 @@
 #include "params/SectorTags.hh"
 
 class BaseReplacementPolicy;
+class ReplaceableEntry;
 
 /**
  * A SectorTags cache tag store.