diff --git a/build_library/toolchain_util.sh b/build_library/toolchain_util.sh
index 4fbd8424d2..dd13442a2b 100644
--- a/build_library/toolchain_util.sh
+++ b/build_library/toolchain_util.sh
@@ -39,7 +39,6 @@ declare -r \
 # Usage: get_portage_arch chost
 get_portage_arch() {
     case "$1" in
-        aarch64*)   echo arm64;;
         alpha*)     echo alpha;;
         arm*)       echo arm;;
         hppa*)      echo hppa;;
@@ -61,7 +60,6 @@ get_portage_arch() {
 # Usage: get_kernel_arch chost
 get_kernel_arch() {
     case "$1" in
-        aarch64*)   echo arm64;;
         alpha*)     echo alpha;;
         arm*)       echo arm;;
         hppa*)      echo parisc;;