diff --git a/SUMMARY.md b/SUMMARY.md
index 972410a..c426eb1 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -22,6 +22,7 @@
     * [Paging](Theory/Paging.md)
     * [Elf64](Theory/ELF.md)
     * [Per-CPU variables](Theory/per-cpu.md)
+    * [Cpumasks]()
     * [Lockdep]()
     * [CPUID]()
     * [MSR]()