diff --git a/conf/qemu_riscv64_virt_defconfig b/conf/qemu_riscv64_virt_defconfig
index 23c6cba15..e614c61b7 100644
--- a/conf/qemu_riscv64_virt_defconfig
+++ b/conf/qemu_riscv64_virt_defconfig
@@ -6,6 +6,7 @@ BR2_RISCV_ABI_LP64D=y
 BR2_GCC_TARGET_ABI="lp64d"
 #
 BR2_TOOLCHAIN_EXTERNAL=y
+BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
 BR2_TOOLCHAIN_EXTERNAL_PATH="$(RISCV)"
 BR2_TOOLCHAIN_EXTERNAL_CUSTOM_PREFIX="$(ARCH)-unknown-linux-gnu"
 BR2_TOOLCHAIN_EXTERNAL_GCC_10=y