diff --git a/server/AyaNova/models/MetricMM.cs b/server/AyaNova/models/MetricMM.cs
index a2a5c4d6..8093d43c 100644
--- a/server/AyaNova/models/MetricMM.cs
+++ b/server/AyaNova/models/MetricMM.cs
@@ -10,6 +10,7 @@ namespace AyaNova.Models
     public class MetricMM
     {
         [Required]
+        [Key]
         public DateTime t { get; set; }
         public long Allocated { get; set; }
         public long WorkingSet { get; set; }