diff --git a/cylc/flow/prerequisite.py b/cylc/flow/prerequisite.py
index 1dedc27bee2..0b5ac6a18d5 100644
--- a/cylc/flow/prerequisite.py
+++ b/cylc/flow/prerequisite.py
@@ -204,7 +204,7 @@ def satisfy_me(self, all_task_outputs):
         # This only gets called for known prerequisites, except in bad or
         # overly wide manual "cylc set" calls.
 
-        satisfied = True
+        satisfied = False
         for message in all_task_outputs:
             if message in self.satisfied:
                 self.satisfied[message] = self.DEP_STATE_SATISFIED