diff --git a/creduce/cvise.example.sh b/creduce/cvise.example.sh
index 617d2ee..ac3827a 100755
--- a/creduce/cvise.example.sh
+++ b/creduce/cvise.example.sh
@@ -18,7 +18,12 @@ if ! command -v yk-config 2>&1 ; then
     exit 1
 fi
 
+# Rebuild with the reduced onelua.c in-place.
+#
+# Note that it's not enough to just copy onelua.c and `Makefile` in. The whole
+# `src` dir is needed.
 cp -r "${YKLUA_HOME}/creduce/src" ./
+cp onelua.c src/
 cd ./src
 
 make onelua