diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt
index d9c6554..e903f20 100644
--- a/Documentation/kbuild/kbuild.txt
+++ b/Documentation/kbuild/kbuild.txt
@@ -28,10 +28,20 @@
 --------------------------------------------------
 Addtional module specific options to use for $(AS).
 
+AFLAGS_KERNEL
+--------------------------------------------------
+Addtional options for $(AS) when used for assembler
+code for code that is compiled as built-in.
+
 KCFLAGS
 --------------------------------------------------
 Additional options to the C compiler (for built-in and modules).
 
+CFLAGS_KERNEL
+--------------------------------------------------
+Addtional options for $(CC) when used to compile
+code that is compiled as built-in.
+
 CFLAGS_MODULE
 --------------------------------------------------
 Addtional module specific options to use for $(CC).