diff --git a/kernel/mem.c b/kernel/mem.c
index a0e74173..49c44010 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -210,7 +210,7 @@ void ihk_mc_unmap_virtual(void *va, int npages, int free_physical)
 	}
 	
 	if (free_physical)
-		ihk_pagealloc_free(vmap_allocator, va, npages);
+		ihk_pagealloc_free(vmap_allocator, (unsigned long)va, npages);
 }
 
 #ifdef ATTACHED_MIC