diff --git a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp
index a6df732c5fc..2e971906650 100644
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp
@@ -44,6 +44,7 @@
 // The solution is to remove this method from the definition
 // of a Space.
 
+class G1CollectedHeap;
 class HeapRegionRemSet;
 class HeapRegionRemSetIterator;
 class HeapRegion;