diff --git a/lib/bingo.rb b/lib/bingo.rb
index 7be2c78..b359ebe 100644
--- a/lib/bingo.rb
+++ b/lib/bingo.rb
@@ -329,11 +329,14 @@ module Bingo
     end
 
     # state: up (≥80 % of probes answered), degraded, down (nothing answered
-    # in the last two buckets), unknown (worker stale, vantage lost, or the
-    # site wasn't probed in the newest bucket).
+    # in the last two buckets), unknown (worker stale, vantage lost, the
+    # site wasn't probed in the newest bucket, or its targets never answered
+    # in the window: a host that is filtered from abroad would otherwise
+    # read as a dark site).
     def site_state(rows, latest, previous, trusted)
       return 'unknown' unless latest && trusted
       cur = rows[latest] or return 'unknown'
+      return 'unknown' if rows.each_value.sum { |r| r[:ok] }.zero?
       prev = previous && rows[previous]
       return 'down' if cur[:ok].zero? && (prev.nil? || prev[:ok].zero?)
       cur[:ok] >= cur[:checks] * 0.8 ? 'up' : 'degraded'
diff --git a/test/status_test.rb b/test/status_test.rb
index 6022189..739777b 100644
--- a/test/status_test.rb
+++ b/test/status_test.rb
@@ -29,6 +29,8 @@ class StatusTest < Minitest::Test
   end
 
   def two_buckets(base = B, **controls)
+    bucket(base - 3600, **controls) # the dark site answered an hour earlier
+    sample(@down, base - 3600, 5)
     [base - 300, base].each do |at|
       bucket(at, **controls)
       sample(@up, at, 5)
@@ -48,6 +50,11 @@ class StatusTest < Minitest::Test
     assert_equal 'ok', r.state
   end
 
+  def test_target_that_never_answered_is_unknown_not_down
+    [B - 300, B].each { |at| bucket(at); sample(@down, at, 0) }
+    assert_equal 'unknown', states(Bingo::Status.load(NOW))['dc-down']
+  end
+
   def test_one_dark_bucket_after_a_good_one_is_not_yet_down
     bucket(B - 300); sample(@down, B - 300, 5)
     bucket(B);       sample(@down, B, 0)