diff --git a/src/cluster.c b/src/cluster.c
index 7637869..77b6f7b 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -83,7 +83,7 @@ int hexagram_cluster_update(hexagram_cluster *cluster,
         }
 
         case 0x288: {
-            cluster->state.temp = 0.75 * (double)(frame->data[4] - 48);
+            cluster->state.temp = 0.75 * (double)(frame->data[1] - 48);
 
             return 1;
         }