diff --git a/libmariadb/mariadb_stmt.c b/libmariadb/mariadb_stmt.c
index a73827a8..c8ce63c8 100644
--- a/libmariadb/mariadb_stmt.c
+++ b/libmariadb/mariadb_stmt.c
@@ -453,7 +453,7 @@ static long ma_get_length(MYSQL_STMT *stmt, unsigned int param_nr, unsigned long
     return stmt->params[param_nr].length[row_nr];
 }
 
-static char ma_get_indicator(MYSQL_STMT *stmt, unsigned int param_nr, unsigned long row_nr)
+static signed char ma_get_indicator(MYSQL_STMT *stmt, unsigned int param_nr, unsigned long row_nr)
 {
   if (!MARIADB_STMT_BULK_SUPPORTED(stmt) ||
       !stmt->array_size ||
@@ -484,7 +484,7 @@ int store_param(MYSQL_STMT *stmt, int column, unsigned char **p, unsigned long r
 {
   void *buf= ma_get_buffer_offset(stmt, stmt->params[column].buffer_type,
                                   stmt->params[column].buffer, row_nr);
-  char indicator= ma_get_indicator(stmt, column, row_nr);
+  signed char indicator= ma_get_indicator(stmt, column, row_nr);
 
   switch (stmt->params[column].buffer_type) {
   case MYSQL_TYPE_TINY:
@@ -896,7 +896,7 @@ unsigned char* mysql_stmt_execute_generate_bulk_request(MYSQL_STMT *stmt, size_t
       {
         size_t size= 0;
         my_bool has_data= TRUE;
-        char indicator= ma_get_indicator(stmt, i, j);
+        signed char indicator= ma_get_indicator(stmt, i, j);
         /* check if we need to send data */
         if (indicator > 0)
           has_data= FALSE;
@@ -930,9 +930,11 @@ unsigned char* mysql_stmt_execute_generate_bulk_request(MYSQL_STMT *stmt, size_t
             size+= 5; /* max 8 bytes for size */
             if (indicator == STMT_INDICATOR_NTS ||
               (!stmt->row_size && ma_get_length(stmt,i,j) == -1))
+            {
                 size+= strlen(ma_get_buffer_offset(stmt,
                                                    stmt->params[i].buffer_type,
                                                    stmt->params[i].buffer,j));
+            }
             else
               size+= (size_t)ma_get_length(stmt, i, j);
             break;
diff --git a/unittest/libmariadb/features-10_2.c b/unittest/libmariadb/features-10_2.c
index d46e6acc..c1228d8e 100644
--- a/unittest/libmariadb/features-10_2.c
+++ b/unittest/libmariadb/features-10_2.c
@@ -194,7 +194,7 @@ static int test_cursor(MYSQL *mysql)
 {
   int rc;
   MYSQL_STMT *stmt;
-  unsigned int prefetch_rows= 1;
+  unsigned long prefetch_rows= 1;
   unsigned long cursor_type= CURSOR_TYPE_READ_ONLY;
 
   stmt= mysql_stmt_init(mysql);
diff --git a/unittest/libmariadb/misc.c b/unittest/libmariadb/misc.c
index 76d1914c..d9433543 100644
--- a/unittest/libmariadb/misc.c
+++ b/unittest/libmariadb/misc.c
@@ -1189,7 +1189,7 @@ static int test_zerofill(MYSQL *mysql)
 static int test_server_status(MYSQL *mysql)
 {
   int rc;
-  unsigned long server_status;
+  unsigned int server_status;
   MYSQL_STMT *stmt= mysql_stmt_init(mysql);
 
   rc= mysql_autocommit(mysql, 1);
diff --git a/unittest/libmariadb/thread.c b/unittest/libmariadb/thread.c
index 4eb25081..6fae38a8 100644
--- a/unittest/libmariadb/thread.c
+++ b/unittest/libmariadb/thread.c
@@ -63,6 +63,9 @@ static int test_conc_27(MYSQL *mysql)
   DWORD threads[THREAD_NUM];
 #endif
 
+  diag("please run this test manually as root");
+  return SKIP;
+
   rc= mysql_query(mysql, "DROP TABLE IF EXISTS t_conc27");
   check_mysql_rc(rc, mysql);