diff --git a/scripts/build-toolchains.sh b/scripts/build-toolchains.sh
index 1897d157..92cd24dc 100755
--- a/scripts/build-toolchains.sh
+++ b/scripts/build-toolchains.sh
@@ -135,7 +135,7 @@ module_all riscv-tests --prefix="${RISCV}/riscv64-unknown-elf"
 
 # Common tools (not in any particular toolchain dir)
 
-SRCDIR="$(pwd)/toolchains" module_all libgloss --prefix="${RISCV}/riscv64-unknown-elf" --host=riscv64-unknown-elf
+CC= CXX= SRCDIR="$(pwd)/toolchains" module_all libgloss --prefix="${RISCV}/riscv64-unknown-elf" --host=riscv64-unknown-elf
 
 if [ -z "$IGNOREQEMU" ] ; then
 SRCDIR="$(pwd)/toolchains" module_all qemu --prefix="${RISCV}" --target-list=riscv64-softmmu