diff --git a/src/main/java/io/orprotocol/Server.java b/src/main/java/io/orprotocol/Server.java
index fbf29e4..dfa705a 100644
--- a/src/main/java/io/orprotocol/Server.java
+++ b/src/main/java/io/orprotocol/Server.java
@@ -237,7 +237,7 @@ public class Server extends WebSocketServer {
                     client.disconnect(ServerFailures.INACTIVITY_TIMEOUT);
                 }
             }
-        }, this.settings.heartbeatInterval, this.settings.heartbeatInterval, TimeUnit.MILLISECONDS);
+        }, this.settings.heartbeatInterval, this.settings.heartbeatInterval, TimeUnit.SECONDS);
     }
 
     /**