diff --git a/lib/strtcpy.h b/lib/strtcpy.h
index 60f44f9f1..25255493a 100644
--- a/lib/strtcpy.h
+++ b/lib/strtcpy.h
@@ -31,7 +31,7 @@
  *	at the buffer pointed to by dst.  If the destination buffer,
  *	isn't large enough to hold the copy, the resulting string is
  *	truncated.  The size of the buffer is calculated internally via
- *	SIZEOF_ARRAY().
+ *	NITEMS().
  *
  * RETURN VALUE
  *	-1	If this call truncated the resulting string.
@@ -44,7 +44,7 @@
  */
 
 
-#define STRTCPY(dst, src)  strtcpy(dst, src, SIZEOF_ARRAY(dst))
+#define STRTCPY(dst, src)  strtcpy(dst, src, NITEMS(dst))
 
 
 inline ssize_t strtcpy(char *restrict dst, const char *restrict src,
diff --git a/lib/utmp.c b/lib/utmp.c
index 7f116f3b7..bf878ce6b 100644
--- a/lib/utmp.c
+++ b/lib/utmp.c
@@ -246,7 +246,7 @@ static
 #ifdef HAVE_STRUCT_UTMP_UT_HOST
 	} else if (   (NULL != ut)
 	           && ('\0' != ut->ut_host[0])) {
-		hostname = XMALLOC(SIZEOF_ARRAY(ut->ut_host) + 1, char);
+		hostname = XMALLOC(NITEMS(ut->ut_host) + 1, char);
 		ZUSTR2STP(hostname, ut->ut_host);
 #endif				/* HAVE_STRUCT_UTMP_UT_HOST */
 	}
diff --git a/lib/zustr2stp.h b/lib/zustr2stp.h
index 2160a1b0a..436f47bcb 100644
--- a/lib/zustr2stp.h
+++ b/lib/zustr2stp.h
@@ -22,7 +22,7 @@
 ({                                                                            \
 	static_assert(!is_array(dst) || sizeof(dst) > SIZEOF_ARRAY(src), ""); \
                                                                               \
-	zustr2stp(dst, src, SIZEOF_ARRAY(src));                               \
+	zustr2stp(dst, src, NITEMS(src));                                     \
 })
 
 
@@ -62,9 +62,9 @@ inline char *zustr2stp(char *restrict dst, const char *restrict src, size_t sz);
  *
  * EXAMPLES
  *	char  src[13] = "Hello, world!"  // No '\0' in this buffer!
- *	char  dst[SIZEOF_ARRAY(src) + 1];
+ *	char  dst[NITEMS(src) + 1];
  *
- *	zustr2stp(dst, src, SIZEOF_ARRAY(src));
+ *	zustr2stp(dst, src, NITEMS(src));
  *	puts(dst);
  */