diff --git a/src/bitutils.h b/src/bitutils.h
index ae3a575..66924bf 100644
--- a/src/bitutils.h
+++ b/src/bitutils.h
@@ -3,7 +3,7 @@
 
 #include "postgres.h"
 
-#include "halfvec.h"			/* for USE_DISPATCH */
+#include "halfvec.h"			/* for USE_DISPATCH and USE_TARGET_CLONES */
 
 /* Check version in first header */
 #if PG_VERSION_NUM < 120000