diff --git a/headers/private/kernel/vm/VMCache.h b/headers/private/kernel/vm/VMCache.h
index 3a916d42f7..8e32d5e29a 100644
--- a/headers/private/kernel/vm/VMCache.h
+++ b/headers/private/kernel/vm/VMCache.h
@@ -73,6 +73,7 @@ public:
 	inline	bool				Lock();
 	inline	bool				TryLock();
 	inline	bool				SwitchLock(mutex* from);
+	inline	bool				SwitchFromReadLock(rw_lock* from);
 			void				Unlock();
 	inline	void				AssertLocked();
 
@@ -220,6 +221,13 @@ VMCache::SwitchLock(mutex* from)
 }
 
 
+bool
+VMCache::SwitchFromReadLock(rw_lock* from)
+{
+	return mutex_switch_from_read_lock(from, &fLock) == B_OK;
+}
+
+
 void
 VMCache::AssertLocked()
 {