diff --git a/fish-rust/src/fd_monitor.rs b/fish-rust/src/fd_monitor.rs
index 05c237abb..3bbb1c7e4 100644
--- a/fish-rust/src/fd_monitor.rs
+++ b/fish-rust/src/fd_monitor.rs
@@ -517,6 +517,9 @@ pub fn add(&self, mut item: FdMonitorItem) -> FdMonitorItemId {
             });
         }
 
+        // Tickle our signaller.
+        self.change_signaller.post();
+
         item_id
     }