Type check all expressions

1 files changed, 1 insertions, 1 deletions

diff --git a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ReferenceNode.java b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ReferenceNode.java
index 56914143e25..cd4eb21d1f2 100755
--- a/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ReferenceNode.java
+++ b/searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/ReferenceNode.java
@@ -110,7 +110,7 @@ public final class ReferenceNode extends CompositeNode {
         // Don't support outputs of different type, for simplicity
         TensorType type = context.getType(toString());
         if (type == null)
-            throw new IllegalArgumentException("Could not determine type of feature " + toString());
+            throw new IllegalArgumentException("Unknown feature '" + toString() + "'");
         return type;
     }