diff --git a/src/halfvec.h b/src/halfvec.h
index aefd3d9..6b76fcb 100644
--- a/src/halfvec.h
+++ b/src/halfvec.h
@@ -6,7 +6,6 @@
 #include <float.h>
 
 #include "bitutils.h"
-#include "vector.h"
 
 #if defined(USE_DISPATCH)
 #define HALFVEC_DISPATCH
@@ -27,7 +26,7 @@
 #define HALF_MAX 65504
 #endif
 
-#define HALFVEC_MAX_DIM VECTOR_MAX_DIM
+#define HALFVEC_MAX_DIM 16000
 
 #define HALFVEC_SIZE(_dim)		(offsetof(HalfVector, x) + sizeof(half)*(_dim))
 #define DatumGetHalfVector(x)	((HalfVector *) PG_DETOAST_DATUM(x))