diff --git a/support/testing/tests/boot/test_syslinux.py b/support/testing/tests/boot/test_syslinux.py
index f25cddfb6c..467d564e18 100644
--- a/support/testing/tests/boot/test_syslinux.py
+++ b/support/testing/tests/boot/test_syslinux.py
@@ -6,6 +6,7 @@ class TestSysLinuxBase(infra.basetest.BRTest):
         """
         BR2_x86_i686=y
         BR2_TOOLCHAIN_EXTERNAL=y
+        BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
         BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
         BR2_TOOLCHAIN_EXTERNAL_URL="http://toolchains.bootlin.com/downloads/releases/toolchains/x86-i686/tarballs/x86-i686--glibc--bleeding-edge-2018.11-1.tar.bz2"
         BR2_TOOLCHAIN_EXTERNAL_GCC_8=y