diff --git a/build.config.aarch64 b/build.config.aarch64
index 4339a3b54d86..0bc0847eb02b 100644
--- a/build.config.aarch64
+++ b/build.config.aarch64
@@ -1,3 +1,6 @@
+echo 'WARNING: Do not source build.config.aarch64.
+    Instead, set kernel_build.make_goals.' >&2
+
 MAKE_GOALS="
 Image
 modules
diff --git a/build.config.arm b/build.config.arm
index d0d7f144c5bb..e17e98fe80aa 100644
--- a/build.config.arm
+++ b/build.config.arm
@@ -1,3 +1,6 @@
+echo 'WARNING: Do not source build.config.arm.
+    Instead, set kernel_build.make_goals.' >&2
+
 MAKE_GOALS="
 zImage
 modules
diff --git a/build.config.common b/build.config.common
index e2bc01457182..61e13af44c4f 100644
--- a/build.config.common
+++ b/build.config.common
@@ -1,3 +1,10 @@
+echo 'WARNING: Do not source build.config.common. Instead:
+    - If you need -D__ANDROID_COMMON_KERNEL__ in KCFLAGS, set kernel_build.kcflags.
+    - If you still have build configs, use:
+        . ${ROOT_DIR}/${KERNEL_DIR}/build.config.constants
+    - If you do not have any build configs, delete kernel_build.build_config entirely.
+' >&2
+
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.constants
 
 KCFLAGS="${KCFLAGS} -D__ANDROID_COMMON_KERNEL__"
diff --git a/build.config.gki.aarch64 b/build.config.gki.aarch64
index 6ed2a4d0aaa3..8d37f6185d74 100644
--- a/build.config.gki.aarch64
+++ b/build.config.gki.aarch64
@@ -3,6 +3,8 @@
 # TODO(b/236012223): Deprecate and remove this file once build-config-less
 #   builds are fully supported.
 
+echo 'WARNING: Do not source build.config.gki.aarch64. See warnings below for details.' >&2
+
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.common
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.aarch64
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.gki
diff --git a/build.config.gki.x86_64 b/build.config.gki.x86_64
index 1098aa19c857..962a3d5f49ed 100644
--- a/build.config.gki.x86_64
+++ b/build.config.gki.x86_64
@@ -3,6 +3,8 @@
 # TODO(b/236012223): Deprecate and remove this file once build-config-less
 #   builds are fully supported.
 
+echo 'WARNING: Do not source build.config.gki.x86_64. See warnings below for details.' >&2
+
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.common
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.x86_64
 . ${ROOT_DIR}/${KERNEL_DIR}/build.config.gki
diff --git a/build.config.x86_64 b/build.config.x86_64
index 3b3ce501bdfb..f251bb299049 100644
--- a/build.config.x86_64
+++ b/build.config.x86_64
@@ -1,3 +1,6 @@
+echo 'WARNING: Do not source build.config.x86_64.
+    Instead, set kernel_build.make_goals.' >&2
+
 MAKE_GOALS="
 bzImage
 modules