diff --git a/packages/lib/link/connectors.js b/packages/lib/link/connectors.js
index 3ae4235b..e2aacdf7 100644
--- a/packages/lib/link/connectors.js
+++ b/packages/lib/link/connectors.js
@@ -163,6 +163,14 @@ class WebSocketBaseConnector extends events.EventEmitter {
 	get closing() {
 		return this._closing || this._state === "closed";
 	}
+
+	/**
+	 * True if the connector currently has a valid session that is either
+	 * connected or in the process of resuming.
+	 */
+	get hasSession() {
+		return ["connected", "resuming"].includes(this._state);
+	}
 }
 
 /**
diff --git a/packages/slave/slave.js b/packages/slave/slave.js
index 5d03bc63..ecc492ed 100755
--- a/packages/slave/slave.js
+++ b/packages/slave/slave.js
@@ -945,6 +945,10 @@ class InstanceConnection extends libLink.Link {
 	}
 
 	async forwardEventToMaster(message, event) {
+		if (!this.slave.connector.hasSession) {
+			return;
+		}
+
 		event.send(this.slave, message.data);
 	}