diff --git a/wiretap/pcapng.c b/wiretap/pcapng.c
index c350532b3f..46662ee988 100644
--- a/wiretap/pcapng.c
+++ b/wiretap/pcapng.c
@@ -1090,12 +1090,6 @@ pcapng_read_packet_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn, wta
                 }
         }
 
-        if (packet.cap_len > packet.packet_len) {
-                *err = WTAP_ERR_BAD_FILE;
-                *err_info = g_strdup_printf("pcapng_read_packet_block: cap_len %u is larger than packet_len %u",
-                    packet.cap_len, packet.packet_len);
-                return 0;
-        }
         if (packet.cap_len > WTAP_MAX_PACKET_SIZE) {
                 *err = WTAP_ERR_BAD_FILE;
                 *err_info = g_strdup_printf("pcapng_read_packet_block: cap_len %u is larger than WTAP_MAX_PACKET_SIZE %u",
diff --git a/wiretap/wtap.c b/wiretap/wtap.c
index 2d04375366..343a9b23c4 100644
--- a/wiretap/wtap.c
+++ b/wiretap/wtap.c
@@ -1075,5 +1075,23 @@ gboolean
 wtap_seek_read(wtap *wth, gint64 seek_off,
 	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
-	return wth->subtype_seek_read(wth, seek_off, phdr, buf, err, err_info);
+	if (!wth->subtype_seek_read(wth, seek_off, phdr, buf, err, err_info))
+		return FALSE;
+
+	/*
+	 * It makes no sense for the captured data length to be bigger
+	 * than the actual data length.
+	 */
+	if (wth->phdr.caplen > wth->phdr.len)
+		wth->phdr.caplen = wth->phdr.len;
+
+	/*
+	 * Make sure that it's not WTAP_ENCAP_PER_PACKET, as that
+	 * probably means the file has that encapsulation type
+	 * but the read routine didn't set this packet's
+	 * encapsulation type.
+	 */
+	g_assert(wth->phdr.pkt_encap != WTAP_ENCAP_PER_PACKET);
+
+	return TRUE;
 }