diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 0b4f17418f64..7e232ba59b86 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -15,9 +15,6 @@
 #include <linux/sched.h>
 #include <linux/sched/coredump.h>
 
-struct stable_node;
-struct mem_cgroup;
-
 #ifdef CONFIG_KSM
 int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
 		unsigned long end, int advice, unsigned long *vm_flags);