diff --git a/libmariadb/my_stmt.c b/libmariadb/my_stmt.c
index 636f573c..60f7e30b 100644
--- a/libmariadb/my_stmt.c
+++ b/libmariadb/my_stmt.c
@@ -1662,7 +1662,7 @@ static my_bool madb_reset_stmt(MYSQL_STMT *stmt, unsigned int flags)
     if (flags & MADB_RESET_SERVER)
     {
       /* reset statement on server side */
-      if (stmt->mysql->status == MYSQL_STATUS_READY)
+      if (stmt->mysql && stmt->mysql->status == MYSQL_STATUS_READY)
       {
         unsigned char cmd_buf[STMT_ID_LENGTH];
         int4store(cmd_buf, stmt->stmt_id);
@@ -1698,6 +1698,14 @@ my_bool STDCALL mysql_stmt_reset(MYSQL_STMT *stmt)
 
   DBUG_ENTER("mysql_stmt_reset");
 
+  if (!mysql)
+  {
+    /* connection could be invalid, e.g. after mysql_stmt_close or failed reconnect
+       attempt (see bug CONC-97) */
+    SET_CLIENT_STMT_ERROR(stmt, CR_SERVER_LOST, SQLSTATE_UNKNOWN, 0);
+    DBUG_RETURN(1); 
+  }
+
   if (stmt->state >= MYSQL_STMT_USER_FETCHING &&
       stmt->fetch_row_func == stmt_unbuffered_fetch)
     flags|= MADB_RESET_BUFFER;
diff --git a/libmariadb/mysql_async.c b/libmariadb/mysql_async.c
index 1a3cf421..57c33aab 100644
--- a/libmariadb/mysql_async.c
+++ b/libmariadb/mysql_async.c
@@ -41,7 +41,7 @@
 */
 #define WIN_SET_NONBLOCKING(mysql) { \
     my_bool old_mode; \
-    if ((mysql)->net.vio) vio_blocking((mysql)->net.vio, FALSE, &old_mode); \
+    if ((mysql)->net.vio) vio_blocking((mysql)->net.vio, FALSE); \
   }
 #else
 #define WIN_SET_NONBLOCKING(mysql)
diff --git a/unittest/libmariadb/ps.c b/unittest/libmariadb/ps.c
index 1b2495dc..5f60ce84 100644
--- a/unittest/libmariadb/ps.c
+++ b/unittest/libmariadb/ps.c
@@ -25,6 +25,24 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 /* Utility function to verify the field members */
 
+static int test_conc97(MYSQL *mysql)
+{
+  MYSQL_STMT *stmt= mysql_stmt_init(mysql);
+  int rc;
+
+  mysql_close(mysql);
+
+  rc= mysql_stmt_reset(stmt);
+  FAIL_IF(!rc, "Error expected while resetting stmt");
+
+  rc= mysql_stmt_close(stmt);
+  check_stmt_rc(rc, stmt);
+
+  mysql= mysql_init(NULL);
+
+  return OK;
+}
+
 static int test_conc83(MYSQL *mysql)
 {
   MYSQL_STMT *stmt;
@@ -4844,6 +4862,7 @@ int test_notrunc(MYSQL *mysql)
 }
 
 struct my_tests_st my_tests[] = {
+  {"test_conc97", test_conc97, TEST_CONNECTION_NEW, 0, NULL, NULL},
   {"test_conc83", test_conc83, TEST_CONNECTION_NEW, 0, NULL, NULL},
   {"test_conc60", test_conc60, TEST_CONNECTION_DEFAULT, 0, NULL, NULL},
   {"test_notrunc", test_notrunc, TEST_CONNECTION_DEFAULT, 0, NULL, NULL},