diff --git a/source/langtags.csv b/source/langtags.csv
index bd88dd3..f2276a0 100644
--- a/source/langtags.csv
+++ b/source/langtags.csv
@@ -3241,6 +3241,8 @@ iso,iso-Latn-NG,Isoko,NG,,,10967,,,,,WAF,iso,,,
 isr,isr-Zxxx-IL,Israeli Sign Language,IL,,,,,,,,WAS,isr,,,
 ist,ist-Latn-HR,Istriot,HR,,,,,1,,,SEU,ist,,,
 isu,isu-Latn-CM,Isu,CM,,,10987,,,,,MAF,isu,LE,12-Jan-2018,
+isv-Cyrl,isv-Cyrl-001,Interslavic,001 BA BG BY CZ HR ME MK PL RS RU SI SK UA,,,,,,,,ANZ EEU NAM SEU WAS WEU,isv,,,
+isv-Latn,isv-Latn-001,Interslavic,001 BA BG BY CZ HR ME MK PL RS RU SI SK UA,,,,,,,,ANZ EEU NAM SEU WAS WEU,isv,,,
 it,it-Latn-IT,Italian,AE AL AR AT AU BA BE BR CA CH CL CZ DE ER FI FR GB HR IL IT LI LU LY MC MT NZ PL PR RO RU SI SM SO TN US UY VA,,,,,,,,ANZ CAR EAF EEU NAF NAM NEU SAM SEU WAS WEU,ita,CLDR,,
 it-Brai,it-Brai-IT,Italian,AE AL AR AT AU BA BE BR CA CH CL CZ DE ER FI FR GB HR IL IT LI LU LY MC MT NZ PL PR RO RU SI SM SO TN US UY VA,,,,,,,,ANZ CAR EAF EEU NAF NAM NEU SAM SEU WAS WEU,ita,,,
 itb,itb-Latn-PH,"Itneg, Binongan",PH,,,,,,,,SEA,itb,,,