diff --git a/src/ivfbuild.c b/src/ivfbuild.c
index fa7a17a..40661b3 100644
--- a/src/ivfbuild.c
+++ b/src/ivfbuild.c
@@ -482,7 +482,7 @@ CreateListPages(Relation index, VectorArray centers, int dimensions,
 	Size		listSize;
 	IvfflatList list;
 
-	listSize = MAXALIGN(IVFFLAT_LIST_SIZE(dimensions));
+	listSize = MAXALIGN(IVFFLAT_LIST_SIZE(VECTOR_SIZE(dimensions)));
 	list = palloc0(listSize);
 
 	buf = IvfflatNewBuffer(index, forkNum);
diff --git a/src/ivfflat.h b/src/ivfflat.h
index 149dc20..3ca6fe9 100644
--- a/src/ivfflat.h
+++ b/src/ivfflat.h
@@ -54,7 +54,7 @@ typedef enum IvfflatType
 #define PROGRESS_IVFFLAT_PHASE_ASSIGN	3
 #define PROGRESS_IVFFLAT_PHASE_LOAD		4
 
-#define IVFFLAT_LIST_SIZE(_dim)	(offsetof(IvfflatListData, center) + VECTOR_SIZE(_dim))
+#define IVFFLAT_LIST_SIZE(size)	(offsetof(IvfflatListData, center) + size)
 
 #define IvfflatPageGetOpaque(page)	((IvfflatPageOpaque) PageGetSpecialPointer(page))
 #define IvfflatPageGetMeta(page)	((IvfflatMetaPageData *) PageGetContents(page))