diff --git a/src/protocol/mod.rs b/src/protocol/mod.rs
index 9ea716fb06b139f56996a305106369224b576835..3352aa183902a1d0ca745f59a08e780944a27e04 100644
--- a/src/protocol/mod.rs
+++ b/src/protocol/mod.rs
@@ -294,4 +294,16 @@ impl EvalContext<'_> {
             },
         }
     }
+    fn did_put(&mut self, port: Value) -> bool {
+        match self {
+            EvalContext::Nonsync(_) => unreachable!("did_put in nonsync context"),
+            EvalContext::Sync(context) => match port {
+                Value::Output(OutputValue(port)) => {
+                    context.is_firing(port).unwrap_or(false)
+                },
+                Value::Input(_) => unreachable!("did_put on input port"),
+                _ => unreachable!("did_put on non-port value")
+            }
+        }
+    }
 }