diff --git a/bootstrap.sh b/bootstrap.sh
index d8bd3b3a8b9..1d32620f63a 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -127,12 +127,11 @@ function install_dep() {
 # 1. Installation of dependencies.
 #
 
-# Wrapper around the `arch` command which plays nice with OS X
+# We should not use the arch command, since it is not reliably
+# available on macOS or some linuxes:
+# https://www.gnu.org/software/coreutils/manual/html_node/arch-invocation.html
 function get_arch() {
-  case $(uname) in
-    Linux) arch;;
-    Darwin) uname -m;;
-  esac
+  uname -m
 }
 
 
diff --git a/dev.env b/dev.env
index 54dd9cb41b9..096dd0aaf7e 100644
--- a/dev.env
+++ b/dev.env
@@ -79,7 +79,7 @@ export PKG_CONFIG_PATH
 
 # According to https://github.com/etcd-io/etcd/blob/a621d807f061e1dd635033a8d6bc261461429e27/Documentation/op-guide/supported-platform.md,
 # currently, etcd is unstable on arm64, so ETCD_UNSUPPORTED_ARCH should be set.
-if [ "$(arch)" == aarch64 ]; then
+if [ "$(uname -m)" == aarch64 ]; then
     export ETCD_UNSUPPORTED_ARCH=arm64
 fi