diff --git a/include/budg.h b/include/budg.h
index 1a5a6630..538ba0be 100644
--- a/include/budg.h
+++ b/include/budg.h
@@ -34,6 +34,8 @@
 #ifndef BUDG_H
 #define BUDG_H
 
+#define SCT_EFFIC (SCT_TYPE_MAX + 1)
+
 void fill_update_array(int *bp, struct sctstr *sp);
 int gt_bg_nmbr(int *bp, struct sctstr *sp, i_type comm);
 void pt_bg_nmbr(int *bp, struct sctstr *sp, i_type comm, int amount);
diff --git a/include/sect.h b/include/sect.h
index 5a06d9d7..d512ebaf 100644
--- a/include/sect.h
+++ b/include/sect.h
@@ -153,7 +153,7 @@ struct dchrstr {
 #define SCT_BTOWER      33	/* Bridge tower */
 #define	SCT_MAXDEF	33	/* highest sector type in header files */
 
-#define SCT_EFFIC       34	/* used in update & budget */
+#define SCT_TYPE_MAX    39
 
 #define getsect(x, y, p) ef_read(EF_SECTOR, sctoff((x), (y)), (p))
 #define putsect(p) ef_write(EF_SECTOR, sctoff((p)->sct_x, (p)->sct_y), (p))
@@ -163,7 +163,7 @@ struct dchrstr {
 /* things relating to sectors */
 extern int sctoff(coord x, coord y);
 
-extern struct dchrstr dchr[SCT_MAXDEF + 2];
+extern struct dchrstr dchr[SCT_TYPE_MAX + 1];
 extern struct dchrstr bigcity_dchr;
 #define IS_BIG_CITY(type) (dchr[(type)].d_pkg == UPKG)
 
diff --git a/src/lib/global/sect.c b/src/lib/global/sect.c
index 3e3aeb31..41623968 100644
--- a/src/lib/global/sect.c
+++ b/src/lib/global/sect.c
@@ -43,8 +43,9 @@
 /*
  * Table of sector designations
  * Initialized on startup from sect.config and deity custom config (if any).
+ * Terminated by a sentinel with null d_name.
  */
-struct dchrstr dchr[SCT_MAXDEF + 2];
+struct dchrstr dchr[SCT_TYPE_MAX + 1];
 
 /*
  * Table of infrastructure types