diff --git a/include/wsrep/client_state.hpp b/include/wsrep/client_state.hpp
index 5f2282e..2944910 100644
--- a/include/wsrep/client_state.hpp
+++ b/include/wsrep/client_state.hpp
@@ -667,21 +667,25 @@ namespace wsrep
         /** @{*/
 
         /**
-         * Enter total order isolation critical section.
+         * Enter total order isolation critical section. If the wait_until
+         * is given non-default value, the operation is retried until
+         * successful, the given time point is reached or the client is
+         * interupted.
          *
          * @param key_array Array of keys
          * @param buffer Buffer containing the action to execute inside
          *               total order isolation section
          * @param flags  Provider flags for TOI operation
-         * @todo Flags argument is not necessary for TOI operation,
-         *       they should always have start_transaction | commit
-         *       when passed to provider.
+         * @param wait_until Time point to wait until for successful
+         *                   certification.
          *
          * @return Zero on success, non-zero otherwise.
          */
-        int enter_toi_local(const wsrep::key_array& key_array,
-                            const wsrep::const_buffer& buffer,
-                            int flags);
+        int enter_toi_local(
+            const wsrep::key_array& key_array,
+            const wsrep::const_buffer& buffer,
+            std::chrono::time_point<std::chrono::steady_clock>
+            wait_until = std::chrono::time_point<std::chrono::steady_clock>());
         /**
          * Enter applier TOI mode
          *
@@ -743,13 +747,20 @@ namespace wsrep
          * the provider, the provider error code can be retrieved
          * by current_error_status() call.
          *
+         * If the wait_until is given non-default value, the operation is
+         * retried until successful, the given time point is reached or the
+         * client is interupted.
+         *
          * @param keys Array of keys for NBO operation.
          * @param buffer NBO write set
-         *
+         * @param wait_until Time point to wait until for successful certification.
          * @return Zero in case of success, non-zero in case of failure.
          */
-        int begin_nbo_phase_one(const wsrep::key_array& keys,
-                                const wsrep::const_buffer& buffer);
+        int begin_nbo_phase_one(
+            const wsrep::key_array& keys,
+            const wsrep::const_buffer& buffer,
+            std::chrono::time_point<std::chrono::steady_clock>
+            wait_until = std::chrono::time_point<std::chrono::steady_clock>());
 
         /**
          * End non-blocking operation phase after aquiring required
@@ -996,7 +1007,7 @@ namespace wsrep
                             enum wsrep::provider::status status =
                             wsrep::provider::success);
 
-        void enter_toi_common();
+        void enter_toi_common(wsrep::unique_lock<wsrep::mutex>&);
         void leave_toi_common();
 
         wsrep::thread::id owning_thread_id_;
diff --git a/src/client_state.cpp b/src/client_state.cpp
index 7928ede..1b8fbf0 100644
--- a/src/client_state.cpp
+++ b/src/client_state.cpp
@@ -330,26 +330,44 @@ void wsrep::client_state::disable_streaming()
 //                                 TOI                                      //
 //////////////////////////////////////////////////////////////////////////////
 
-void wsrep::client_state::enter_toi_common()
+void wsrep::client_state::enter_toi_common(
+    wsrep::unique_lock<wsrep::mutex>& lock)
 {
-    wsrep::unique_lock<wsrep::mutex> lock(mutex_);
+    assert(lock.owns_lock());
     toi_mode_ = mode_;
     mode(lock, m_toi);
 }
 
 int wsrep::client_state::enter_toi_local(const wsrep::key_array& keys,
                                          const wsrep::const_buffer& buffer,
-                                         int flags)
+                                         std::chrono::time_point<std::chrono::steady_clock> wait_until)
 {
     debug_log_state("enter_toi_local: enter");
     assert(state_ == s_exec);
     assert(mode_ == m_local);
     int ret;
-    switch (provider().enter_toi(id_, keys, buffer, toi_meta_, flags))
+
+    enum wsrep::provider::status status;
+    wsrep::unique_lock<wsrep::mutex> lock(mutex_);
+    // Poll until timeout expires or the client is interrupted.
+    do
+    {
+        lock.unlock();
+        status = provider().enter_toi(id_, keys, buffer, toi_meta_,
+                                      wsrep::provider::flag::start_transaction |
+                                      wsrep::provider::flag::commit);
+        lock.lock();
+    }
+    while (status == wsrep::provider::error_certification_failed &&
+           wait_until.time_since_epoch().count() &&
+           wait_until < std::chrono::steady_clock::now() &&
+           not client_service_.interrupted(lock));
+
+    switch (status)
     {
     case wsrep::provider::success:
     {
-        enter_toi_common();
+        enter_toi_common(lock);
         ret = 0;
         break;
     }
@@ -366,8 +384,9 @@ int wsrep::client_state::enter_toi_local(const wsrep::key_array& keys,
 void wsrep::client_state::enter_toi_mode(const wsrep::ws_meta& ws_meta)
 {
     debug_log_state("enter_toi_mode: enter");
+    wsrep::unique_lock<wsrep::mutex> lock(mutex_);
     assert(mode_ == m_high_priority);
-    enter_toi_common();
+    enter_toi_common(lock);
     toi_meta_ = ws_meta;
     debug_log_state("enter_toi_mode: leave");
 }
@@ -455,8 +474,10 @@ int wsrep::client_state::end_rsu()
 //                                 NBO                                       //
 ///////////////////////////////////////////////////////////////////////////////
 
-int wsrep::client_state::begin_nbo_phase_one(const wsrep::key_array& keys,
-                                             const wsrep::const_buffer& buffer)
+int wsrep::client_state::begin_nbo_phase_one(
+    const wsrep::key_array& keys,
+    const wsrep::const_buffer& buffer,
+    std::chrono::time_point<std::chrono::steady_clock> wait_until)
 {
     debug_log_state("begin_nbo_phase_one: enter");
     wsrep::unique_lock<wsrep::mutex> lock(mutex_);
@@ -464,16 +485,19 @@ int wsrep::client_state::begin_nbo_phase_one(const wsrep::key_array& keys,
     assert(mode_ == m_local);
     assert(toi_mode_ == m_undefined);
 
-    /**
-     * @todo Implement retrying if the call fails due to certification
-     * failure.
-     */
-    lock.unlock();
-    enum wsrep::provider::status status(
-        provider().enter_toi(
-            id_, keys, buffer, toi_meta_,
-            wsrep::provider::flag::start_transaction));
-    lock.lock();
+    enum wsrep::provider::status status;
+    // Poll until timeout expires or the client is interrupted.
+    do
+    {
+        lock.unlock();
+        status = provider().enter_toi(id_, keys, buffer, toi_meta_,
+                                      wsrep::provider::flag::start_transaction);
+        lock.lock();
+    }
+    while (status == wsrep::provider::error_certification_failed &&
+           wait_until.time_since_epoch().count() &&
+           wait_until < std::chrono::steady_clock::now() &&
+           not client_service_.interrupted(lock));
     int ret;
     switch (status)
     {
diff --git a/test/toi_test.cpp b/test/toi_test.cpp
index f629e40..e637017 100644
--- a/test/toi_test.cpp
+++ b/test/toi_test.cpp
@@ -33,9 +33,7 @@ BOOST_FIXTURE_TEST_CASE(test_toi_mode,
     key.append_key_part("k2", 2);
     wsrep::key_array keys{key};
     wsrep::const_buffer buf("toi", 3);
-    BOOST_REQUIRE(cc.enter_toi_local(keys, buf,
-                                     wsrep::provider::flag::start_transaction |
-                                     wsrep::provider::flag::commit) == 0);
+    BOOST_REQUIRE(cc.enter_toi_local(keys, buf) == 0);
     BOOST_REQUIRE(cc.mode() == wsrep::client_state::m_toi);
     BOOST_REQUIRE(cc.in_toi());
     BOOST_REQUIRE(cc.toi_mode() == wsrep::client_state::m_local);