diff --git a/meta/classes-recipe/kernel.bbclass b/meta/classes-recipe/kernel.bbclass
index 46da867a63..ab064bb085 100644
--- a/meta/classes-recipe/kernel.bbclass
+++ b/meta/classes-recipe/kernel.bbclass
@@ -246,6 +246,12 @@ UBOOT_LOADADDRESS ?= "${UBOOT_ENTRYPOINT}"
 # Some Linux kernel configurations need additional parameters on the command line
 KERNEL_EXTRA_ARGS ?= ""
 
+# The kernel builds out of tree in ${B}, which kernel-arch does not remap.
+# Map it to KERNEL_SRC_PATH as well, so generated sources are recorded under
+# the same root as the rest of the kernel and are not collected into a
+# ${PN}-src package. The last matching prefix map wins.
+KERNEL_CC:append = " -ffile-prefix-map=${B}=${KERNEL_SRC_PATH}"
+
 EXTRA_OEMAKE += ' ARCH="${@oe.kernel.map_kernel_arch(d)}"'
 EXTRA_OEMAKE += ' CC="${KERNEL_CC}" LD="${KERNEL_LD}" OBJCOPY="${KERNEL_OBJCOPY}" STRIP="${KERNEL_STRIP}"'
 EXTRA_OEMAKE += ' HOSTCC="${BUILD_CC}" HOSTCFLAGS="${BUILD_CFLAGS}" HOSTLDFLAGS="${BUILD_LDFLAGS}" HOSTCPP="${BUILD_CPP}"'