diff --git a/src/host/Host.cc b/src/host/Host.cc
index f2d2dfeace..9a6f072a07 100644
--- a/src/host/Host.cc
+++ b/src/host/Host.cc
@@ -56,8 +56,9 @@ const char * Host::db_names = "(oid,host_name,state,im_mad,vm_mad,"
                               "tm_mad,last_mon_time)";
 
 const char * Host::db_bootstrap = "CREATE TABLE host_pool ("
-	"oid INTEGER PRIMARY KEY,host_name TEXT,state INTEGER,"
-	"im_mad TEXT,vm_mad TEXT,tm_mad TEXT,last_mon_time INTEGER)";
+    "oid INTEGER PRIMARY KEY,host_name TEXT,state INTEGER,"
+    "im_mad TEXT,vm_mad TEXT,tm_mad TEXT,last_mon_time INTEGER, "
+    "UNIQUE(host_name, im_mad, vm_mad, tm_mad) )";
 
 /* -------------------------------------------------------------------------- */
 /* -------------------------------------------------------------------------- */