diff --git a/src/propeller/problems/PSB1/small_or_large.cljc b/src/propeller/problems/PSB1/small_or_large.cljc
index ca6512d..d3106e4 100644
--- a/src/propeller/problems/PSB1/small_or_large.cljc
+++ b/src/propeller/problems/PSB1/small_or_large.cljc
@@ -27,7 +27,7 @@
       ;;; close
       (list 'close)
       ;;; ERCs (constants)
-      (list "small" "large" random-int))))
+      (list "" "small" "large" random-int))))
 
 (defn error-function
   [argmap data individual]