diff --git a/RECIPE-API-CHANGELOG.md b/RECIPE-API-CHANGELOG.md
index 7a16b5c2..ae845674 100644
--- a/RECIPE-API-CHANGELOG.md
+++ b/RECIPE-API-CHANGELOG.md
@@ -492,3 +492,12 @@ Recipes inheriting dpkg-base now automatically have a bitbake target
 exists for the current `DISTRO_ARCH`.
 In that case the compat package can be built by adding `<foo>-compat`
 to `DEPENDS` or `IMAGE_INSTALL`.
+
+### "Prefetch" mode for base-apt
+
+Originally, `base-apt` repo is created only during second build when variable
+ISAR_USE_CACHED_BASE_REPO is set. The repo is populated with every package that
+took part in the first build and was cached in DL_DIR.
+
+New ISAR_PREFETCH_BASE_APT variable changes the way `base-apt` is populated.
+Packages added to the repo before any step they are requested.
diff --git a/meta-isar/conf/local.conf.sample b/meta-isar/conf/local.conf.sample
index 7e0184e4..2d3c9c1e 100644
--- a/meta-isar/conf/local.conf.sample
+++ b/meta-isar/conf/local.conf.sample
@@ -215,6 +215,10 @@ ISAR_CROSS_COMPILE ?= "0"
 # does not access the network
 #BB_NO_NETWORK ?= "1"
 
+# Comment out for switching to old base-apt behaviour when it's populated
+# at the beginnig of the second build
+ISAR_PREFETCH_BASE_APT ?= "1"
+
 # Set root password to 'root'
 # Password was encrypted using following command:
 #   mkpasswd -m sha512crypt -R 10000