diff --git a/sys/geom/part/g_part_gpt.c b/sys/geom/part/g_part_gpt.c
--- a/sys/geom/part/g_part_gpt.c
+++ b/sys/geom/part/g_part_gpt.c
@@ -1045,6 +1045,20 @@
 		g_free(sectbl);
 	}
 
+	/*
+	 * The reserved area preceeds the valid area for partitions. Warn when
+	 * the lba_start doesn't meet the standard's minimum size for the gpt
+	 * entry array. UEFI 2.10 section 5.3 specifies that the LBA must be 32
+	 * (for 512 byte sectors) or 6 (4k sectors) or larger. This is different
+	 * than the number of valid entries in the GPT entry array, which can be
+	 * smaller.
+	 */
+	if (table->hdr->hdr_lba_start < GPT_MIN_RESERVED / pp->sectorsize + 2) {
+		printf("GEOM: warning: %s lba_start %llu < required min %d\n",
+		    pp->name, (unsigned long long)table->hdr->hdr_lba_start,
+		    GPT_MIN_RESERVED / pp->sectorsize + 2);
+	}
+
 	basetable->gpt_first = table->hdr->hdr_lba_start;
 	basetable->gpt_last = table->hdr->hdr_lba_end;
 	basetable->gpt_entries = table->hdr->hdr_entries;