diff --git a/installer/data/mysql/atomicupdate/bug_20245-update_slovak-language-code.sql b/installer/data/mysql/atomicupdate/bug_20245-update_slovak-language-code.sql
new file mode 100644
index 0000000000..871f5f0866
--- /dev/null
+++ b/installer/data/mysql/atomicupdate/bug_20245-update_slovak-language-code.sql
@@ -0,0 +1 @@
+UPDATE language_rfc4646_to_iso639 SET iso639_2_code = 'slo' WHERE iso639_2_code = 'slk' AND rfc4646_subtag = 'sk';
diff --git a/installer/data/mysql/mandatory/subtag_registry.sql b/installer/data/mysql/mandatory/subtag_registry.sql
index ebcdedcc29..87858d78dd 100755
--- a/installer/data/mysql/mandatory/subtag_registry.sql
+++ b/installer/data/mysql/mandatory/subtag_registry.sql
@@ -922,7 +922,7 @@ INSERT INTO language_subtag_registry( subtag, type, description, added)
 VALUES ( 'sk', 'language', 'Slovak','2014-10-30');
 
 INSERT INTO language_rfc4646_to_iso639(rfc4646_subtag,iso639_2_code)
-VALUES ( 'sk','slk');
+VALUES ( 'sk','slo');
 
 INSERT INTO language_descriptions(subtag, type, lang, description)
 VALUES ( 'sk', 'language', 'sk', 'Slovenčina');