diff --git a/src/lib/common/xundump.c b/src/lib/common/xundump.c
index 53a647b7..41a87e29 100644
--- a/src/lib/common/xundump.c
+++ b/src/lib/common/xundump.c
@@ -60,6 +60,7 @@
 #include <time.h>
 #include "file.h"
 #include "match.h"
+#include "nat.h"
 #include "nsc.h"
 #include "optlist.h"
 #include "xdump.h"
@@ -130,7 +131,7 @@ ca0_is_id(int type)
 static int
 can_fill_gaps(int type)
 {
-    return (ca0_is_id(type) || type == EF_SECTOR)
+    return (ca0_is_id(type) || type == EF_SECTOR || type == EF_REALM)
 	&& !have_hardcoded_indexes(type);
 }
 
@@ -393,6 +394,40 @@ rowid_sect(void)
     return id;
 }
 
+/*
+ * Get the current row's ID.
+ * Current table's type must be EF_REALM.
+ * Return ID on success, -1 on failure.
+ */
+static int
+rowid_realm(void)
+{
+    int fldno_cnum, fldno_realm, id;
+    long realm, cnum;
+
+    if (CANT_HAPPEN(partno != 0 || cur_type != EF_REALM))
+	return -1;
+
+    fldno_cnum = fld_find_long_by_name("cnum", 0);
+    fldno_realm = fld_find_long_by_name("realm", 0);
+    if (fldno_cnum < 0 || fldno_realm < 0)
+	return cur_id + 1;
+
+    realm = (long)fldval[fldno_realm].val_as.dbl;
+    cnum = (long)fldval[fldno_cnum].val_as.dbl;
+    if (cnum < 0 || cnum >= MAXNOC)
+	return gripe("Field %d must be between 0 and %d",
+		     fldno_cnum, MAXNOC);
+    if (realm < 0 || realm >= MAXNOR)
+	return gripe("Field %d must be between 0 and %d",
+		     fldno_realm, MAXNOR);
+    id = realm + cnum * MAXNOR;
+    if (id <= cur_id)
+	return gripe("Fields %d,%d must be > (%d,%d)",
+		     fldno_cnum + 1, fldno_realm + 1,
+		     cur_id / MAXNOR, cur_id % MAXNOR);
+    return id;
+}
 /*
  * Get the current row's object.
  * Extend the table if necessary.
@@ -420,6 +455,10 @@ rowobj(void)
 	id = rowid_sect();
 	if (id < 0)
 	    return NULL;
+    } else if (cur_type == EF_REALM) {
+	id = rowid_realm();
+	if (id < 0)
+	    return NULL;
     } else
 	id = last_id + 1;
     if (id > ef_id_limit(cur_type)) {
diff --git a/tests/empdump/errors.err b/tests/empdump/errors.err
index ea76e977..01f71735 100644
--- a/tests/empdump/errors.err
+++ b/tests/empdump/errors.err
@@ -46,6 +46,9 @@ tests/empdump/xundump-errors/fld-invid2:3: Field 1 must be > -1
 tests/empdump/xundump-errors/fld-invid3:4: Field 1 must be > 2
 tests/empdump/xundump-errors/fld-invid4:3: Field 1 must be <= 98
 tests/empdump/xundump-errors/fld-invid5:4: Coordinates in fields 1,2 must be > 2,0
+tests/empdump/xundump-errors/fld-invid6:3: Field 0 must be between 0 and 99
+tests/empdump/xundump-errors/fld-invid7:3: Field 1 must be between 0 and 50
+tests/empdump/xundump-errors/fld-invid8:4: Fields 1,2 must be > (0,1)
 tests/empdump/xundump-errors/fld-junk:2: Junk in field 1
 tests/empdump/xundump-errors/fld-junk2:2: Junk in field 19
 tests/empdump/xundump-errors/fld-malnum:2: Malformed number in field 1
diff --git a/tests/empdump/errors.status b/tests/empdump/errors.status
index da7383b0..bd9eb7c9 100644
--- a/tests/empdump/errors.status
+++ b/tests/empdump/errors.status
@@ -70,6 +70,9 @@
 1
 1
 1
+1
+1
+1
 0
 1
 0
diff --git a/tests/empdump/xundump-errors/fld-constnum b/tests/empdump/xundump-errors/fld-constnum
index 410ad88e..9317c0f3 100644
--- a/tests/empdump/xundump-errors/fld-constnum
+++ b/tests/empdump/xundump-errors/fld-constnum
@@ -1,4 +1,4 @@
-config realm
-cnum realm xl xh yl yh
-1 0 0 0 0 0
+config sect
+xloc yloc ...
+64 0
 # Value for field 1 must be 0
diff --git a/tests/empdump/xundump-errors/fld-invid6 b/tests/empdump/xundump-errors/fld-invid6
new file mode 100644
index 00000000..af877ba3
--- /dev/null
+++ b/tests/empdump/xundump-errors/fld-invid6
@@ -0,0 +1,4 @@
+config realm
+cnum realm ...
+100 0
+# Field 0 must be between 0 and 99
diff --git a/tests/empdump/xundump-errors/fld-invid7 b/tests/empdump/xundump-errors/fld-invid7
new file mode 100644
index 00000000..491df9b2
--- /dev/null
+++ b/tests/empdump/xundump-errors/fld-invid7
@@ -0,0 +1,4 @@
+config realm
+cnum realm ...
+0 100
+# Field 1 must be between 0 and 50
diff --git a/tests/empdump/xundump-errors/fld-invid8 b/tests/empdump/xundump-errors/fld-invid8
new file mode 100644
index 00000000..6a69789a
--- /dev/null
+++ b/tests/empdump/xundump-errors/fld-invid8
@@ -0,0 +1,5 @@
+config realm
+cnum realm ...
+0 1
+0 0
+# Fields 1,2 must be > (0,1)