diff --git a/sys/sys/disk/gpt.h b/sys/sys/disk/gpt.h
index e48b13684814..596a5cba1681 100644
--- a/sys/sys/disk/gpt.h
+++ b/sys/sys/disk/gpt.h
@@ -82,6 +82,13 @@ struct gpt_hdr {
 CTASSERT(offsetof(struct gpt_hdr, padding) == 92);
 #endif
 
+/*
+ * The GPT standard (section 5.3 of UEFI standard version 2.10) requires
+ * we reserve at least 16k after the PMBR and the GPT header for the GPT
+ * Array Entries.
+ */
+#define GPT_MIN_RESERVED	16384
+
 struct gpt_ent {
 	gpt_uuid_t	ent_type;
 	gpt_uuid_t	ent_uuid;
diff --git a/usr.bin/mkimg/gpt.c b/usr.bin/mkimg/gpt.c
index 59c51a6a177b..ed3f008c394f 100644
--- a/usr.bin/mkimg/gpt.c
+++ b/usr.bin/mkimg/gpt.c
@@ -24,7 +24,7 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
+#include <sys/param.h>
 #include <sys/errno.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -124,13 +124,21 @@ crc32(const void *buf, size_t sz)
 	return (crc ^ ~0U);
 }
 
+/*
+ * Return the number of sectors needed to store the partition table.
+ */
 static u_int
 gpt_tblsz(void)
 {
-	u_int ents;
+	u_int eps;		/* Entries per Sector */
 
-	ents = secsz / sizeof(struct gpt_ent);
-	return ((nparts + ents - 1) / ents);
+	/*
+	 * Count the number of sectors needed for the GPT Entry Array to store
+	 * the number of partitions defined for this image.  Enforce the 16kB
+	 * minimum space for the GPT Entry Array per UEFI v2.10 Section 5.3.
+	 */
+	eps = secsz / sizeof(struct gpt_ent);
+	return (MAX(howmany(GPT_MIN_RESERVED, secsz), howmany(nparts, eps)));
 }
 
 static lba_t