diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 98bf21aa0..7a3793461 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -92,7 +92,7 @@ jobs:
     env:
       VERBOSE: true
       TIMEOUT: 30
-      LOW_TIMEOUT: 0.07
+      LOW_TIMEOUT: 0.14
       DRIVER: ${{ matrix.driver }}
       REDIS_BRANCH: ${{ matrix.redis }}
     steps:
diff --git a/makefile b/makefile
index 80fc6062e..307e75c30 100644
--- a/makefile
+++ b/makefile
@@ -11,6 +11,7 @@ PORT               := 6381
 SLAVE_PORT         := 6382
 SLAVE_PID_PATH     := ${BUILD_DIR}/redis_slave.pid
 SLAVE_SOCKET_PATH  := ${BUILD_DIR}/redis_slave.sock
+HA_GROUP_NAME      := master1
 SENTINEL_PORTS     := 6400 6401 6402
 SENTINEL_PID_PATHS := $(addprefix ${TMP}/redis,$(addsuffix .pid,${SENTINEL_PORTS}))
 CLUSTER_PORTS      := 7000 7001 7002 7003 7004 7005
@@ -24,7 +25,7 @@ endef
 
 all: start_all test stop_all
 
-start_all: start start_slave start_sentinel start_cluster create_cluster
+start_all: start start_slave start_sentinel wait_for_sentinel start_cluster create_cluster
 
 stop_all: stop_sentinel stop_slave stop stop_cluster
 
@@ -67,10 +68,10 @@ start_sentinel: ${BINARY}
 		conf=${TMP}/sentinel$$port.conf;\
 		touch $$conf;\
 		echo '' >  $$conf;\
-		echo 'sentinel monitor                 master1 127.0.0.1 ${PORT} 2' >> $$conf;\
-		echo 'sentinel down-after-milliseconds master1 5000'                >> $$conf;\
-		echo 'sentinel failover-timeout        master1 30000'               >> $$conf;\
-		echo 'sentinel parallel-syncs          master1 1'                   >> $$conf;\
+		echo 'sentinel monitor                 ${HA_GROUP_NAME} 127.0.0.1 ${PORT} 2' >> $$conf;\
+		echo 'sentinel down-after-milliseconds ${HA_GROUP_NAME} 5000'                >> $$conf;\
+		echo 'sentinel failover-timeout        ${HA_GROUP_NAME} 30000'               >> $$conf;\
+		echo 'sentinel parallel-syncs          ${HA_GROUP_NAME} 1'                   >> $$conf;\
 		${BINARY} $$conf\
 			--daemonize yes\
 			--pidfile   ${TMP}/redis$$port.pid\
@@ -78,6 +79,17 @@ start_sentinel: ${BINARY}
 			--sentinel;\
 	done
 
+wait_for_sentinel:
+	@for port in ${SENTINEL_PORTS}; do\
+		while : ; do\
+			if [ $$(${REDIS_CLIENT} -p $${port} SENTINEL SLAVES ${HA_GROUP_NAME} | wc -l) -gt 1 ]; then\
+				break;\
+			fi;\
+			echo 'Waiting for Redis sentinel to be ready...';\
+			sleep 1;\
+		done;\
+	done
+
 stop_cluster:
 	@$(call kill-redis,${CLUSTER_PID_PATHS})
 	@rm -f appendonly.aof || true
diff --git a/test/cluster_commands_on_keys_test.rb b/test/cluster_commands_on_keys_test.rb
index 124a28709..011bbfadd 100644
--- a/test/cluster_commands_on_keys_test.rb
+++ b/test/cluster_commands_on_keys_test.rb
@@ -49,8 +49,7 @@ def test_object
     assert_equal 1, redis.object('refcount', 'mylist')
     expected_encoding = version < '3.2.0' ? 'ziplist' : 'quicklist'
     assert_equal expected_encoding, redis.object('encoding', 'mylist')
-    expected_instance_type = RUBY_VERSION < '2.4.0' ? Fixnum : Integer
-    assert_instance_of expected_instance_type, redis.object('idletime', 'mylist')
+    assert(redis.object('idletime', 'mylist') >= 0)
 
     redis.set('foo', 1000)
     assert_equal 'int', redis.object('encoding', 'foo')
diff --git a/test/cluster_commands_on_pub_sub_test.rb b/test/cluster_commands_on_pub_sub_test.rb
index 1599dd798..66c166d96 100644
--- a/test/cluster_commands_on_pub_sub_test.rb
+++ b/test/cluster_commands_on_pub_sub_test.rb
@@ -56,13 +56,13 @@ def test_publish_psubscribe_punsubscribe_pubsub
     messages = {}
 
     wire = Wire.new do
-      redis.psubscribe('cha*', 'her*') do |on|
+      redis.psubscribe('guc*', 'her*') do |on|
         on.psubscribe { |_c, t| sub_cnt = t }
         on.punsubscribe { |_c, t| sub_cnt = t }
         on.pmessage do |_ptn, chn, msg|
           messages[chn] = msg
           # FIXME: blocking occurs when `unsubscribe` method was called with channel arguments
-          redis.punsubscribe if messages.size == 3
+          redis.punsubscribe if messages.size == 2
         end
       end
     end
@@ -72,30 +72,27 @@ def test_publish_psubscribe_punsubscribe_pubsub
     publisher = build_another_client
 
     assert_equal [], publisher.pubsub(:channels)
-    assert_equal [], publisher.pubsub(:channels, 'cha*')
-    assert_equal [], publisher.pubsub(:channels, 'her*')
+    assert_equal [], publisher.pubsub(:channels, 'bur*')
     assert_equal [], publisher.pubsub(:channels, 'guc*')
+    assert_equal [], publisher.pubsub(:channels, 'her*')
     assert_equal({}, publisher.pubsub(:numsub))
-    assert_equal({ 'channel1' => 0, 'channel2' => 0, 'hermes3' => 0, 'gucci4' => 0 },
-                 publisher.pubsub(:numsub, 'channel1', 'channel2', 'hermes3', 'gucci4'))
+    assert_equal({ 'burberry1' => 0, 'gucci2' => 0, 'hermes3' => 0 }, publisher.pubsub(:numsub, 'burberry1', 'gucci2', 'hermes3'))
     assert_equal 2, publisher.pubsub(:numpat)
 
-    publisher.publish('chanel1', 'one')
-    publisher.publish('chanel2', 'two')
+    publisher.publish('burberry1', 'one')
+    publisher.publish('gucci2', 'two')
     publisher.publish('hermes3', 'three')
-    publisher.publish('gucci4', 'four')
 
     wire.join
 
-    assert_equal({ 'chanel1' => 'one', 'chanel2' => 'two', 'hermes3' => 'three' }, messages.sort.to_h)
+    assert_equal({ 'gucci2' => 'two', 'hermes3' => 'three' }, messages.sort.to_h)
 
     assert_equal [], publisher.pubsub(:channels)
-    assert_equal [], publisher.pubsub(:channels, 'cha*')
-    assert_equal [], publisher.pubsub(:channels, 'her*')
+    assert_equal [], publisher.pubsub(:channels, 'bur*')
     assert_equal [], publisher.pubsub(:channels, 'guc*')
+    assert_equal [], publisher.pubsub(:channels, 'her*')
     assert_equal({}, publisher.pubsub(:numsub))
-    assert_equal({ 'channel1' => 0, 'channel2' => 0, 'hermes3' => 0, 'gucci4' => 0 },
-                 publisher.pubsub(:numsub, 'channel1', 'channel2', 'hermes3', 'gucci4'))
+    assert_equal({ 'burberry1' => 0, 'gucci2' => 0, 'hermes3' => 0 }, publisher.pubsub(:numsub, 'burberry1', 'gucci2', 'hermes3'))
     assert_equal 0, publisher.pubsub(:numpat)
   end
 end