diff --git a/src/mounts.js b/src/mounts.js
index 590ecbc8f..46fb1e72e 100644
--- a/src/mounts.js
+++ b/src/mounts.js
@@ -158,7 +158,8 @@ async function tryAddMount(volume, options) {
         if (!safe.fs.writeFileSync(keyFilePath, `${volume.mountOptions.privateKey}\n`, { mode: 0o600 })) throw new BoxError(BoxError.FS_ERROR, safe.error);
     }
 
-    await safe(shell.promises.sudo('addMount', [ ADD_MOUNT_CMD, renderMountFile(volume), options.timeout ], {}));
+    const [error] = await safe(shell.promises.sudo('addMount', [ ADD_MOUNT_CMD, renderMountFile(volume), options.timeout ], {}));
+    if (error && error.code === 2) throw new BoxError(BoxError.MOUNT_ERROR, 'Failed to unmount existing mount'); // at this point, the old mount config is still there
 
     const status = await getStatus(volume.mountType, volume.hostPath);
     if (status.state !== 'active') {  // cleanup
diff --git a/src/scripts/addmount.sh b/src/scripts/addmount.sh
index 70bc10fec..0ec4eb93c 100755
--- a/src/scripts/addmount.sh
+++ b/src/scripts/addmount.sh
@@ -27,9 +27,13 @@ mount_filename=$(systemd-escape -p --suffix=mount "$where")
 mount_file="/etc/systemd/system/${mount_filename}"
 
 # cleanup any previous mount of same name (after midway box crash?)
-if systemctl -q is-active mnt-volumes-ext4data.mount; then
+if systemctl -q is-active "${mount_filename}"; then
     echo "Previous mount active, unmounting"
-    systemctl stop "${mount_filename}" || true
+    # unmounting can fail if a user is cd'ed into the directory. if we go ahead and mount anyway, systemd says "active" because it's referring to the previous mount config
+    if ! systemctl stop "${mount_filename}"; then
+        echo "Failed to unmount"
+        exit 2
+    fi
 fi
 
 echo "$mount_file_contents" > "${mount_file}"
@@ -38,7 +42,7 @@ systemctl daemon-reload
 
 if ! timeout "${timeout}" systemctl enable --now "${mount_filename}"; then
     echo "Failed to mount"
-    exit 1
+    exit 3
 fi
 
 echo "Mount succeeded"