diff --git a/tools/testing/selftests/bpf/test_bpftool_build.sh b/tools/testing/selftests/bpf/test_bpftool_build.sh
index 2db3c60e1e61a3c9d6b52dc7256899868e996d98..4e27a90aac29c2de7618bccf3d9c0d4be3ff496e 100755
--- a/tools/testing/selftests/bpf/test_bpftool_build.sh
+++ b/tools/testing/selftests/bpf/test_bpftool_build.sh
@@ -107,6 +107,10 @@ echo -e "... through kbuild\n"
 
 if [ -f ".config" ] ; then
 	make_and_clean tools/bpf
+	## "make tools/bpf" sets $(OUTPUT) to ...tools/bpf/runqslower for
+	## runqslower, but the default (used for the "clean" target) is .output.
+	## Let's make sure we clean runqslower's directory properly.
+	make -C tools/bpf/runqslower OUTPUT=${KDIR_ROOT_DIR}/tools/bpf/runqslower/ clean
 
 	## $OUTPUT is overwritten in kbuild Makefile, and thus cannot be passed
 	## down from toplevel Makefile to bpftool's Makefile.