diff --git a/roles/debian_server/files/btrfs-scrub b/roles/debian_server/files/btrfs-scrub
index ac980d35477713f3f7284d53a0c3bd9a5c3a9483..28e124011e5d2548d2bcdd5c83eacd05f0a450be 100755
--- a/roles/debian_server/files/btrfs-scrub
+++ b/roles/debian_server/files/btrfs-scrub
@@ -5,6 +5,9 @@ for mp in $(lsblk --list --noheadings --output fstype,mountpoint | \
             awk '$1 == "btrfs" {print $2}' | \
             sort -u)
 do
+    # In case there are no btrfs volumes, the for loop will execute once with an
+    # empty string for mp. Validate that indeed we're passed a mountpoint.
+    [ -d "$mp" ] || continue
     status="$(btrfs scrub status "$mp" | awk '$1 == "Status:" {print $2}')"
     if [ "$status" = 'running' ]
     then