1 files changed, 4 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/prelude/query/CompositeTaggableItem.java b/container-search/src/main/java/com/yahoo/prelude/query/CompositeTaggableItem.java
index b1912e4128d..dd015b5f040 100644
--- a/container-search/src/main/java/com/yahoo/prelude/query/CompositeTaggableItem.java
+++ b/container-search/src/main/java/com/yahoo/prelude/query/CompositeTaggableItem.java
@@ -27,6 +27,10 @@ public abstract class CompositeTaggableItem extends CompositeItem implements Tag
 
     /** See {@link TaggableItem#setConnectivity} */
     public void setConnectivity(Item item, double connectivity) {
+        if (!(item instanceof TaggableItem)) {
+            throw new IllegalArgumentException("setConnectivity item must be taggable, was: "
+                                               + item.getClass() + " [" + item + "]");
+        }
         setHasUniqueID(true);
         item.setHasUniqueID(true);
         if (connectedItem != null) {