diff --git a/src/main/java/com/loafle/bridge/discoveryhistory/DiscoveryHistory.java b/src/main/java/com/loafle/bridge/discoveryhistory/DiscoveryHistory.java
index 1aeb8c7..8fd98f4 100644
--- a/src/main/java/com/loafle/bridge/discoveryhistory/DiscoveryHistory.java
+++ b/src/main/java/com/loafle/bridge/discoveryhistory/DiscoveryHistory.java
@@ -25,6 +25,7 @@ public class DiscoveryHistory
     private Boolean result;
 
     @Column(nullable=false)
+    @OneToOne
     private DiscoveryZone zone;
 
     public DiscoveryZone getZone() {