diff --git a/mysql-test/suite/rpl/r/rpl_semi_sync_no_missed_ack_after_add_slave.result b/mysql-test/suite/rpl/r/rpl_semi_sync_no_missed_ack_after_add_slave.result
index 4b21435d2b5..8034314c90f 100644
--- a/mysql-test/suite/rpl/r/rpl_semi_sync_no_missed_ack_after_add_slave.result
+++ b/mysql-test/suite/rpl/r/rpl_semi_sync_no_missed_ack_after_add_slave.result
@@ -3,7 +3,7 @@ connection server_1;
 set @old_enabled= @@global.rpl_semi_sync_master_enabled;
 set @old_timeout= @@global.rpl_semi_sync_master_timeout;
 set global rpl_semi_sync_master_enabled= 1;
-set global rpl_semi_sync_master_timeout= 500;
+set global rpl_semi_sync_master_timeout= 2000;
 connection server_2;
 include/stop_slave.inc
 set @old_enabled= @@global.rpl_semi_sync_slave_enabled;
@@ -14,15 +14,26 @@ include/start_slave.inc
 connection server_3;
 include/stop_slave.inc
 set @old_enabled= @@global.rpl_semi_sync_slave_enabled;
+set @old_dbug= @@global.debug_dbug;
 set global rpl_semi_sync_slave_enabled= 1;
+set global debug_dbug="+d,simulate_delay_semisync_slave_reply";
 include/start_slave.inc
 # Ensure primary recognizes both replicas are semi-sync
 connection server_1;
-connection server_1;
-create table t1 (a int);
+connection default;
+create table t1 (a int);;
+# Ensure both slaves get the event with the need_ack flag set (i.e. one
+# slave shouldn't be able to receive the event and send an ACK before
+# the dump thread for the other server prepares the event to send).
+connection server_3;
+set debug_sync= "now wait_for io_thd_at_slave_reply";
+connection server_2;
+set debug_sync= "now wait_for io_thd_at_slave_reply";
+connection server_3;
+set debug_sync= "now signal io_thd_do_reply";
+connection default;
 connection server_2;
 # Verifying server_2 did not send ACK
-set debug_sync= "now wait_for io_thd_at_slave_reply";
 connection server_3;
 # Verifying server_3 did send ACK
 connection server_1;
@@ -33,12 +44,13 @@ set debug_sync= "now signal io_thd_do_reply";
 #
 # Cleanup
 connection server_2;
+include/stop_slave.inc
 set global rpl_semi_sync_slave_enabled= @old_enabled;
 set global debug_dbug= @old_dbug;
-include/stop_slave.inc
 connection server_3;
-set global rpl_semi_sync_slave_enabled= @old_enabled;
 include/stop_slave.inc
+set global rpl_semi_sync_slave_enabled= @old_enabled;
+set global debug_dbug= @old_dbug;
 connection server_1;
 set global rpl_semi_sync_master_enabled= @old_enabled;
 set global rpl_semi_sync_master_timeout= @old_timeout;
diff --git a/mysql-test/suite/rpl/t/rpl_semi_sync_no_missed_ack_after_add_slave.test b/mysql-test/suite/rpl/t/rpl_semi_sync_no_missed_ack_after_add_slave.test
index 2a74bfc80e5..9d8f87b4345 100644
--- a/mysql-test/suite/rpl/t/rpl_semi_sync_no_missed_ack_after_add_slave.test
+++ b/mysql-test/suite/rpl/t/rpl_semi_sync_no_missed_ack_after_add_slave.test
@@ -26,7 +26,7 @@
 set @old_enabled= @@global.rpl_semi_sync_master_enabled;
 set @old_timeout= @@global.rpl_semi_sync_master_timeout;
 set global rpl_semi_sync_master_enabled= 1;
-set global rpl_semi_sync_master_timeout= 500;
+set global rpl_semi_sync_master_timeout= 2000; # 2s
 
 --connection server_2
 --source include/stop_slave.inc
@@ -39,7 +39,9 @@ set global debug_dbug="+d,simulate_delay_semisync_slave_reply";
 --connection server_3
 --source include/stop_slave.inc
 set @old_enabled= @@global.rpl_semi_sync_slave_enabled;
+set @old_dbug= @@global.debug_dbug;
 set global rpl_semi_sync_slave_enabled= 1;
+set global debug_dbug="+d,simulate_delay_semisync_slave_reply";
 --source include/start_slave.inc
 
 --echo # Ensure primary recognizes both replicas are semi-sync
@@ -55,13 +57,26 @@ if (`SELECT strcmp("$master_ss_status", "ON") != 0`)
   --die rpl_semi_sync_master_status should be ON to start
 }
 
---connection server_1
+--connection default
 --let $init_master_yes_tx= query_get_value(SHOW STATUS LIKE 'rpl_semi_sync_master_yes_tx', Value, 1)
-create table t1 (a int);
+--send create table t1 (a int);
+
+--echo # Ensure both slaves get the event with the need_ack flag set (i.e. one
+--echo # slave shouldn't be able to receive the event and send an ACK before
+--echo # the dump thread for the other server prepares the event to send).
+--connection server_3
+set debug_sync= "now wait_for io_thd_at_slave_reply";
+--connection server_2
+set debug_sync= "now wait_for io_thd_at_slave_reply";
+--connection server_3
+set debug_sync= "now signal io_thd_do_reply";
+
+--connection default
+--reap
+
 
 --connection server_2
 --echo # Verifying server_2 did not send ACK
-set debug_sync= "now wait_for io_thd_at_slave_reply";
 --let $slave1_sent_ack= query_get_value(SHOW STATUS LIKE 'rpl_semi_sync_slave_send_ack', Value, 1)
 if (`SELECT $slave1_sent_ack`)
 {
@@ -71,10 +86,6 @@ if (`SELECT $slave1_sent_ack`)
 
 --connection server_3
 --echo # Verifying server_3 did send ACK
---let $status_var= Rpl_semi_sync_slave_send_ack
---let $status_var_comparsion= >
---let $status_var_value= 0
---source include/wait_for_status_var.inc
 --let $slave2_sent_ack= query_get_value(SHOW STATUS LIKE 'rpl_semi_sync_slave_send_ack', Value, 1)
 if (`SELECT NOT $slave2_sent_ack`)
 {
@@ -108,13 +119,14 @@ set debug_sync= "now signal io_thd_do_reply";
 --echo # Cleanup
 
 --connection server_2
+--source include/stop_slave.inc
 set global rpl_semi_sync_slave_enabled= @old_enabled;
 set global debug_dbug= @old_dbug;
---source include/stop_slave.inc
 
 --connection server_3
-set global rpl_semi_sync_slave_enabled= @old_enabled;
 --source include/stop_slave.inc
+set global rpl_semi_sync_slave_enabled= @old_enabled;
+set global debug_dbug= @old_dbug;
 
 --connection server_1
 set global rpl_semi_sync_master_enabled= @old_enabled;