diff --git a/libmariadb/mariadb_lib.c b/libmariadb/mariadb_lib.c
index 0bba6132..758a8c68 100644
--- a/libmariadb/mariadb_lib.c
+++ b/libmariadb/mariadb_lib.c
@@ -3532,6 +3532,7 @@ static void mysql_once_init()
 }
 
 #ifdef _WIN32
+static INIT_ONCE init_once = (INIT_ONCE)INIT_ONCE_STATIC_INIT;
 BOOL CALLBACK win_init_once(
   PINIT_ONCE InitOnce,
   PVOID Parameter,
@@ -3540,6 +3541,8 @@ BOOL CALLBACK win_init_once(
   return !mysql_once_init();
   return TRUE;
 }
+#else
+static pthread_once_t init_once = PTHREAD_ONCE_INIT;
 #endif
 
 int STDCALL mysql_server_init(int argc __attribute__((unused)),
@@ -3547,11 +3550,9 @@ int STDCALL mysql_server_init(int argc __attribute__((unused)),
   char **groups __attribute__((unused)))
 {
 #ifdef _WIN32
-  static INIT_ONCE init_once = INIT_ONCE_STATIC_INIT;
   BOOL ret = InitOnceExecuteOnce(&init_once, win_init_once, NULL, NULL);
   return ret? 0: 1;
 #else
-  static pthread_once_t init_once = PTHREAD_ONCE_INIT;
   return pthread_once(&init_once, mysql_once_init);
 #endif
 }
@@ -3572,6 +3573,11 @@ void STDCALL mysql_server_end(void)
 #endif
   mysql_client_init= 0;
   ma_init_done= 0;
+#ifdef WIN32
+  init_once = (INIT_ONCE)INIT_ONCE_STATIC_INIT;
+#else
+  init_once = (pthread_once_t)PTHREAD_ONCE_INIT;
+#endif
 }
 
 my_bool STDCALL mysql_thread_init(void)
diff --git a/unittest/libmariadb/CMakeLists.txt b/unittest/libmariadb/CMakeLists.txt
index eba3cb53..9cea9163 100644
--- a/unittest/libmariadb/CMakeLists.txt
+++ b/unittest/libmariadb/CMakeLists.txt
@@ -26,7 +26,7 @@ INCLUDE_DIRECTORIES(${CC_SOURCE_DIR}/include
                     ${CC_SOURCE_DIR}/unittest/libmariadb)
 ADD_DEFINITIONS(-DLIBMARIADB)
 
-SET(API_TESTS "bulk1" "performance" "basic-t" "fetch" "charset" "logs" "cursor" "errors" "view" "ps" "ps_bugs" "sp" "result" "connection" "misc" "ps_new" "thread" "features-10_2" "bulk1")
+SET(API_TESTS "conc336" "bulk1" "performance" "basic-t" "fetch" "charset" "logs" "cursor" "errors" "view" "ps" "ps_bugs" "sp" "result" "connection" "misc" "ps_new" "thread" "features-10_2" "bulk1")
 IF(WITH_DYNCOL)
   SET(API_TESTS ${API_TESTS} "dyncol")
 ENDIF()