diff --git a/cmake/find/mysqlclient.cmake b/cmake/find/mysqlclient.cmake
index 8c97247b886..634681d98f6 100644
--- a/cmake/find/mysqlclient.cmake
+++ b/cmake/find/mysqlclient.cmake
@@ -14,7 +14,7 @@ endif()
 
 option(USE_INTERNAL_MYSQL_LIBRARY "Set to FALSE to use system mysqlclient library instead of bundled" ${NOT_UNBUNDLED})
 
-if(NOT EXISTS "${ClickHouse_SOURCE_DIR}/contrib/mariadb-connector-c/README.md")
+if(NOT EXISTS "${ClickHouse_SOURCE_DIR}/contrib/mariadb-connector-c/README")
     if(USE_INTERNAL_MYSQL_LIBRARY)
         message(WARNING "submodule contrib/mariadb-connector-c is missing. to fix try run: \n git submodule update --init --recursive")
         message (${RECONFIGURE_MESSAGE_LEVEL} "Can't find internal mysql library")
diff --git a/contrib/mariadb-connector-c b/contrib/mariadb-connector-c
index 43249300abf..21f451d4d31 160000
--- a/contrib/mariadb-connector-c
+++ b/contrib/mariadb-connector-c
@@ -1 +1 @@
-Subproject commit 43249300abfe4eb6d3e200ff2aaf1f182f9c0aff
+Subproject commit 21f451d4d3157ffed31ec60a8b76c407190e66bd