diff --git a/docs/manual/adding-packages-directory.txt b/docs/manual/adding-packages-directory.txt
index 6145f54479..e56e59aa96 100644
--- a/docs/manual/adding-packages-directory.txt
+++ b/docs/manual/adding-packages-directory.txt
@@ -218,6 +218,12 @@ use in the comment.
 ** Dependency symbol: +BR2_USE_MMU+
 ** Comment string: no comment to be added
 
+* Kernel headers
+** Dependency symbol: +BR2_TOOLCHAIN_HEADERS_AT_LEAST_X_Y+, (replace
+   +X_Y+ with the proper version, see +toolchain/toolchain-common.in+)
+** Comment string: +headers >= X.Y+ (replace +X.Y+ with the
+   proper version)
+
 * C library
 ** Dependency symbol: +BR2_TOOLCHAIN_USES_GLIBC+,
 +BR2_TOOLCHAIN_USES_UCLIBC+