diff --git a/spec/api/connections_spec.cr b/spec/api/connections_spec.cr
index c4cfbfbf7a..506e3ab99c 100644
--- a/spec/api/connections_spec.cr
+++ b/spec/api/connections_spec.cr
@@ -139,7 +139,7 @@ describe LavinMQ::HTTP::ConnectionsController do
         with_channel(s, user: "arnold", password: "pw") do
           response = http.delete("/api/connections/username/arnold", headers: hdrs)
           response.status_code.should eq 204
-          sleep 0.1
+          sleep 0.1.seconds
           response = http.get("/api/connections/username/arnold", headers: hdrs)
           body = JSON.parse(response.body)
           body.as_a.empty?.should be_true
diff --git a/spec/api/consumers_spec.cr b/spec/api/consumers_spec.cr
index 059849d92d..1ca9c65269 100644
--- a/spec/api/consumers_spec.cr
+++ b/spec/api/consumers_spec.cr
@@ -34,7 +34,7 @@ describe LavinMQ::HTTP::ConsumersController do
         with_channel(s) do |ch|
           q = ch.queue("")
           q.subscribe { }
-          sleep 0.01
+          sleep 10.milliseconds
           response = http.get("/api/consumers/%2f")
           response.status_code.should eq 200
           body = JSON.parse(response.body)
@@ -59,7 +59,7 @@ describe LavinMQ::HTTP::ConsumersController do
         with_channel(s) do |ch|
           q = ch.queue("")
           consumer = q.subscribe { }
-          sleep 0.01
+          sleep 10.milliseconds
           conn = s.connections.to_a.last.name
           response = http.delete("/api/consumers/%2f/#{URI.encode_path(conn)}/#{ch.id}/#{consumer}")
           response.status_code.should eq 204
@@ -74,7 +74,7 @@ describe LavinMQ::HTTP::ConsumersController do
         with_channel(s) do |ch|
           q = ch.queue("")
           consumer = q.subscribe { }
-          sleep 0.01
+          sleep 10.milliseconds
           response = http.delete("/api/consumers/%2f/#{URI.encode_path("abc")}/#{ch.id}/#{consumer}")
           response.status_code.should eq 404
         end
@@ -87,7 +87,7 @@ describe LavinMQ::HTTP::ConsumersController do
           conn = s.connections.first.name
           q = ch.queue("")
           consumer = q.subscribe { }
-          sleep 0.01
+          sleep 10.milliseconds
           response = http.delete("/api/consumers/%2f/#{URI.encode_path(conn)}/123/#{consumer}")
           response.status_code.should eq 404
         end
@@ -100,7 +100,7 @@ describe LavinMQ::HTTP::ConsumersController do
           conn = s.connections.first.name
           q = ch.queue("")
           q.subscribe { }
-          sleep 0.01
+          sleep 10.milliseconds
           response = http.delete("/api/consumers/%2f/#{URI.encode_path(conn)}/#{ch.id}/test")
           response.status_code.should eq 404
         end
diff --git a/spec/api/definitions_spec.cr b/spec/api/definitions_spec.cr
index 29fab99079..079e8ed5bd 100644
--- a/spec/api/definitions_spec.cr
+++ b/spec/api/definitions_spec.cr
@@ -173,7 +173,7 @@ describe LavinMQ::HTTP::Server do
         response.status_code.should eq 200
         # Because we run shovels in a new Fiber we have to make sure the shovel is not started
         # after this spec has finished
-        sleep 0.1 # Start the shovel
+        sleep 0.1.seconds # Start the shovel
         wait_for do
           shovels = s.vhosts["/"].shovels.not_nil!
           shovels.each_value.all? &.running?
diff --git a/spec/api/queues_spec.cr b/spec/api/queues_spec.cr
index 460a42e319..900eb42575 100644
--- a/spec/api/queues_spec.cr
+++ b/spec/api/queues_spec.cr
@@ -318,7 +318,7 @@ describe LavinMQ::HTTP::QueuesController do
         with_channel(s) do |ch|
           q = ch.queue("q3", auto_delete: false, durable: true, exclusive: false)
           q.publish "m1"
-          sleep 0.05
+          sleep 0.05.milliseconds
           body = %({
           "count": 1,
           "ack_mode": "reject_requeue_true",
@@ -380,7 +380,7 @@ describe LavinMQ::HTTP::QueuesController do
         with_channel(s) do |ch|
           q = ch.queue("q5", auto_delete: false, durable: true, exclusive: false)
           q.publish "m1"
-          sleep 0.05
+          sleep 0.05.milliseconds
           body = %({
           "count": 2,
           "ack_mode": "get",
@@ -414,7 +414,7 @@ describe LavinMQ::HTTP::QueuesController do
         with_channel(s) do |ch|
           q = ch.queue("q7")
           q.publish "m1"
-          sleep 0.05
+          sleep 0.05.milliseconds
           body = %({
           "count": 1,
           "ack_mode": "get",
@@ -433,7 +433,7 @@ describe LavinMQ::HTTP::QueuesController do
         with_channel(s) do |ch|
           q = ch.queue("q8")
           q.publish "m1"
-          sleep 0.05
+          sleep 0.05.milliseconds
           body = %({
           "count": 1,
           "ack_mode": "get",
diff --git a/spec/clustering_spec.cr b/spec/clustering_spec.cr
index d6f91b8881..3b48493314 100644
--- a/spec/clustering_spec.cr
+++ b/spec/clustering_spec.cr
@@ -18,7 +18,7 @@ describe LavinMQ::Clustering::Client do
     client = HTTP::Client.new("127.0.0.1", 2379)
     i = 0
     loop do
-      sleep 0.02
+      sleep 0.02.seconds
       response = client.get("/version")
       if response.status.ok?
         next if response.body.includes? "not_decided"
@@ -99,25 +99,25 @@ describe LavinMQ::Clustering::Client do
     rescue LavinMQ::Etcd::Error
       # expect this when etcd nodes are terminated
     end
-    sleep 0.5
+    sleep 0.5.seconds
     spawn(name: "failover1") do
       controller1.run
     end
     spawn(name: "failover2") do
       controller2.run
     end
-    sleep 0.1
+    sleep 0.1.seconds
     leader = listen.receive
     case leader
     when /1$/
       controller1.stop
       listen.receive.should match /2$/
-      sleep 0.1
+      sleep 0.1.seconds
       controller2.stop
     when /2$/
       controller2.stop
       listen.receive.should match /1$/
-      sleep 0.1
+      sleep 0.1.seconds
       controller1.stop
     else fail("no leader elected")
     end
diff --git a/spec/etcd_spec.cr b/spec/etcd_spec.cr
index eaecae93a6..3d611a6bee 100644
--- a/spec/etcd_spec.cr
+++ b/spec/etcd_spec.cr
@@ -29,7 +29,7 @@ describe LavinMQ::Etcd do
         # expect this when etcd nodes are terminated
       end
       w.receive # sync
-      sleep 0.05
+      sleep 50.milliseconds
       etcd.put "foo", "bar"
       w.receive.should eq "bar"
       etcd.put "foo", "rab"
@@ -162,7 +162,7 @@ class EtcdCluster
       i = 0
       client = HTTP::Client.new("127.0.0.1", 23000 + port)
       loop do
-        sleep 0.02
+        sleep 0.02.seconds
         response = client.get("/version")
         if response.status.ok?
           next if response.body.includes? "not_decided"
diff --git a/spec/flow_spec.cr b/spec/flow_spec.cr
index ecd9fdc1c5..856208121f 100644
--- a/spec/flow_spec.cr
+++ b/spec/flow_spec.cr
@@ -16,7 +16,7 @@ describe "Flow" do
         ch.flow(false)
         msgs.pop.ack
         q.publish "msg"
-        sleep 0.05 # wait little so a new message could be delivered
+        sleep 50.milliseconds # wait little so a new message could be delivered
         msgs.size.should eq 0
         ch.flow(true)
         wait_for { msgs.size == 1 }
diff --git a/spec/policies_spec.cr b/spec/policies_spec.cr
index c9117a10c9..2f883b5ef7 100644
--- a/spec/policies_spec.cr
+++ b/spec/policies_spec.cr
@@ -28,10 +28,10 @@ describe LavinMQ::VHost do
     PoliciesSpec.with_vhost do |vhost|
       vhost.queues["test1"] = LavinMQ::Queue.new(vhost, "test")
       vhost.add_policy("test", "^.*$", "all", definitions, -10_i8)
-      sleep 0.01
+      sleep 10.milliseconds
       vhost.queues["test1"].policy.try(&.name).should eq "test"
       vhost.delete_policy("test")
-      sleep 0.01
+      sleep 10.milliseconds
       vhost.queues["test1"].policy.should be_nil
     end
   end
@@ -59,7 +59,7 @@ describe LavinMQ::VHost do
       defs = {"max-length" => JSON::Any.new(1_i64)} of String => JSON::Any
       vhost.queues["test"] = LavinMQ::Queue.new(vhost, "test")
       vhost.add_policy("ml", "^.*$", "queues", defs, 11_i8)
-      sleep 0.01
+      sleep 10.milliseconds
       vhost.queues["test"].policy.not_nil!.name.should eq "ml"
     end
   end
@@ -70,7 +70,7 @@ describe LavinMQ::VHost do
       vhost.queues["test2"] = LavinMQ::Queue.new(vhost, "test")
       vhost.add_policy("ml2", "^.*$", "queues", defs, 1_i8)
       vhost.add_policy("ml1", "^.*$", "queues", defs, 0_i8)
-      sleep 0.01
+      sleep 10.milliseconds
       vhost.queues["test2"].policy.not_nil!.name.should eq "ml2"
     end
   end
@@ -102,7 +102,7 @@ describe LavinMQ::VHost do
         end
         ch.queue_declare("policy-ttl", passive: true)[:message_count].should eq 10
         s.vhosts["/"].add_policy("ttl", "^.*$", "all", defs, 12_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         ch.queue_declare("policy-ttl", passive: true)[:message_count].should eq 0
         s.vhosts["/"].delete_policy("ttl")
       end
@@ -116,7 +116,7 @@ describe LavinMQ::VHost do
         q = ch.queue("qttl")
         q.publish_confirm ""
         s.vhosts["/"].add_policy("qttl", "^.*$", "all", defs, 12_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         expect_raises(AMQP::Client::Channel::ClosedException) do
           ch.queue_declare("qttl", passive: true)
         end
@@ -131,9 +131,9 @@ describe LavinMQ::VHost do
         ch.queue("qttl")
         queue = s.vhosts["/"].queues["qttl"]
         first = queue.last_get_time
-        sleep 0.1
+        sleep 0.1.seconds
         s.vhosts["/"].add_policy("qttl", "^.*$", "all", defs, 12_i8)
-        sleep 0.1
+        sleep 0.1.seconds
         last = queue.last_get_time
         last.should be > first
       end
@@ -149,9 +149,9 @@ describe LavinMQ::VHost do
         q.publish_confirm "short2"
         q.publish_confirm "long"
         ch.queue_declare("max-length-bytes", passive: true)[:message_count].should eq 3
-        sleep 0.02
+        sleep 0.02.seconds
         s.vhosts["/"].add_policy("max-length-bytes", "^.*$", "all", defs, 12_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         ch.queue_declare("max-length-bytes", passive: true)[:message_count].should eq 2
         q.get(no_ack: true).try(&.body_io.to_s).should eq("short2")
         q.get(no_ack: true).try(&.body_io.to_s).should eq("long")
@@ -166,7 +166,7 @@ describe LavinMQ::VHost do
       with_channel(s) do |ch|
         q = ch.queue("max-length-bytes", exclusive: true)
         s.vhosts["/"].add_policy("max-length-bytes", "^.*$", "all", defs, 12_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         q.publish_confirm "short1"
         q.publish_confirm "short2"
         q.publish_confirm "long"
@@ -185,7 +185,7 @@ describe LavinMQ::VHost do
       with_channel(s) do |ch|
         q = ch.queue("max-length-bytes", exclusive: true)
         s.vhosts["/"].add_policy("max-length-bytes", "^.*$", "all", defs, 12_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         q.publish_confirm "short1"
         q.publish_confirm "short2"
         q.publish_confirm "long"
@@ -256,7 +256,7 @@ describe LavinMQ::VHost do
                               "delayed-message"}
         vhost.queues["test"] = LavinMQ::Queue.new(vhost, "test")
         vhost.add_policy("test", "^.*$", "all", definitions, -10_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         vhost.queues["test"].details_tuple[:effective_policy_definition].as(Hash(String, JSON::Any)).each_key do |k|
           supported_policies.includes?(k).should be_true
         end
@@ -272,11 +272,11 @@ describe LavinMQ::VHost do
         vhost.exchanges["x-with-ae"] = LavinMQ::DirectExchange.new(vhost, "x-with-ae",
           arguments: AMQ::Protocol::Table.new({"x-alternate-exchange": "ae2"}))
         vhost.add_policy("test", ".*", "all", definitions, 100_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         vhost.exchanges["no-ae"].@alternate_exchange.should eq "dead-letters"
         vhost.exchanges["x-with-ae"].@alternate_exchange.should eq "ae2"
         vhost.delete_policy("test")
-        sleep 0.01
+        sleep 10.milliseconds
         vhost.exchanges["no-ae"].@alternate_exchange.should be_nil
         vhost.exchanges["x-with-ae"].@alternate_exchange.should eq "ae2"
       end
@@ -287,11 +287,11 @@ describe LavinMQ::VHost do
         vhost.queues["test1"] = LavinMQ::Queue.new(vhost, "test1", arguments: LavinMQ::AMQP::Table.new({"x-max-length" => 1_i64}))
         vhost.queues["test2"] = LavinMQ::Queue.new(vhost, "test2", arguments: LavinMQ::AMQP::Table.new({"x-max-length" => 11_i64}))
         vhost.add_policy("test", ".*", "all", definitions, 100_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         vhost.queues["test1"].@max_length.should eq 1
         vhost.queues["test2"].@max_length.should eq 10
         vhost.delete_policy("test")
-        sleep 0.01
+        sleep 10.milliseconds
         vhost.queues["test1"].@max_length.should eq 1
         vhost.queues["test2"].@max_length.should eq 11
       end
diff --git a/spec/queue_spec.cr b/spec/queue_spec.cr
index 013fcd421f..cf8f9399d6 100644
--- a/spec/queue_spec.cr
+++ b/spec/queue_spec.cr
@@ -276,7 +276,7 @@ describe LavinMQ::Queue do
         sq = s.vhosts["/"].queues[q.name]
         sq.unacked_count.should eq 1
         msg.not_nil!.ack
-        sleep 0.01
+        sleep 10.milliseconds
         sq.unacked_count.should eq 0
       end
     end
@@ -296,7 +296,7 @@ describe LavinMQ::Queue do
         sq = s.vhosts["/"].queues[q.name]
         sq.unacked_count.should eq 1
         msg.ack
-        sleep 0.01
+        sleep 10.milliseconds
         sq.unacked_count.should eq 0
       end
     end
@@ -342,7 +342,7 @@ describe LavinMQ::Queue do
         sub = q.subscribe(no_ack: true) { |_| }
         Dir.exists?(data_dir).should be_true
         q.unsubscribe(sub)
-        sleep 0.1
+        sleep 0.1.seconds
         Dir.exists?(data_dir).should be_false
       end
     end
diff --git a/spec/server_spec.cr b/spec/server_spec.cr
index 0823be8cc1..7139f9146c 100644
--- a/spec/server_spec.cr
+++ b/spec/server_spec.cr
@@ -140,7 +140,7 @@ describe LavinMQ::Server do
         q.unbind(x.name, "")
         x.publish("m1", q.name)
         code.receive.should eq 404
-        sleep 0.01
+        sleep 10.milliseconds
         ch.closed?.should be_true
       end
     end
@@ -206,9 +206,9 @@ describe LavinMQ::Server do
       with_channel(s) do |ch|
         q = ch.queue
         q.publish_confirm "expired", props: AMQP::Client::Properties.new(expiration: "1")
-        sleep 0.2
+        sleep 0.2.seconds
         q.publish_confirm "expired", props: AMQP::Client::Properties.new(expiration: "1")
-        sleep 0.2
+        sleep 0.2.seconds
         msg = q.get(no_ack: true)
         msg.should be_nil
       end
@@ -363,7 +363,7 @@ describe LavinMQ::Server do
         ch.prefetch 1
         q.subscribe(no_ack: false) do |msg|
           mch.send msg
-          sleep 0.2
+          sleep 0.2.seconds
           msg.ack
         end
         10.times do |i|
@@ -422,7 +422,7 @@ describe LavinMQ::Server do
         msgs = [] of AMQP::Client::DeliverMessage
         tag = q.subscribe { |msg| msgs << msg }
         q.unsubscribe(tag)
-        sleep 0.01
+        sleep 10.milliseconds
         ch.has_subscriber?(tag).should eq false
       end
     end
@@ -462,7 +462,7 @@ describe LavinMQ::Server do
         x.publish "m2", q.name, props: AMQP::Client::Properties.new(headers: hdrs)
         msgs = Channel(AMQP::Client::DeliverMessage).new(2)
         q.subscribe { |msg| msgs.send msg }
-        spawn { sleep 5; msgs.close }
+        spawn { sleep 5.seconds; msgs.close }
         2.times { msgs.receive?.should_not be_nil }
       end
     end
@@ -569,7 +569,7 @@ describe LavinMQ::Server do
     with_amqp_server do |s|
       with_channel(s) do |ch|
         ch.basic_ack(0, multiple: true)
-        sleep 0.01
+        sleep 10.milliseconds
         ch.basic_ack(0, multiple: true)
       end
     end
@@ -639,7 +639,7 @@ describe LavinMQ::Server do
         q.publish_confirm("m2").should be_true
         definitions = {"max-length" => JSON::Any.new(1_i64)} of String => JSON::Any
         s.vhosts["/"].add_policy("test", "^mlq$", "queues", definitions, 10_i8)
-        sleep 0.01
+        sleep 10.milliseconds
         s.vhosts["/"].queues["mlq"].message_count.should eq 1
       end
     end
@@ -840,7 +840,7 @@ describe LavinMQ::Server do
         q1.bind(x1.name, "rk")
         q2.bind(x1.name, "rk")
         x1.publish("m1", "rk")
-        sleep 0.05
+        sleep 0.05.milliseconds
         msg_q1 = q1.get(no_ack: true)
         msg_q2 = q2.get(no_ack: true)
         msg_q1.not_nil!.body_io.to_s.should eq("m1")
@@ -885,11 +885,11 @@ describe LavinMQ::Server do
         5.times { q.publish "" }
         delivered = 0
         tag = q.subscribe(no_ack: false) { |_m| delivered += 1 }
-        sleep 0.05
+        sleep 0.05.milliseconds
         q.unsubscribe(tag)
-        sleep 0.05
+        sleep 0.05.milliseconds
         ch.basic_recover(requeue: true)
-        sleep 0.05
+        sleep 0.05.milliseconds
         q.delete[:message_count].should eq 5
       end
     end
@@ -1042,7 +1042,7 @@ describe LavinMQ::Server do
     with_amqp_server do |s|
       with_channel(s) do |ch|
         ch.basic_ack(1)
-        sleep 0.1
+        sleep 0.1.seconds
         expect_raises(AMQP::Client::Channel::ClosedException, /PRECONDITION_FAILED - unknown delivery tag 1/) do
           ch.basic_ack(1)
         end
@@ -1062,7 +1062,7 @@ describe LavinMQ::Server do
         _msg3 = ch.basic_get(q.name, no_ack: false)
         msg2.not_nil!.ack
         msg2.not_nil!.ack # this will trigger the error
-        sleep 0.1
+        sleep 0.1.seconds
         expect_raises(AMQP::Client::Channel::ClosedException, /PRECONDITION_FAILED - unknown delivery tag 2/) do
           msg1.not_nil!.ack
         end
@@ -1082,7 +1082,7 @@ describe LavinMQ::Server do
         msg3 = ch.basic_get(q.name, no_ack: false)
         msg2.not_nil!.ack
         msg2.not_nil!.ack(multiple: true) # this should tigger a precondition fail
-        sleep 0.1
+        sleep 0.1.seconds
         expect_raises(AMQP::Client::Channel::ClosedException, /PRECONDITION_FAILED - unknown delivery tag 2/) do
           msg3.not_nil!.ack
         end
@@ -1102,7 +1102,7 @@ describe LavinMQ::Server do
         end
         q.publish "1"
         ch.@connection.@io.as(TCPSocket).close
-        sleep 0.05
+        sleep 0.05.milliseconds
         count.should eq 0
 
         Fiber.yield
diff --git a/spec/shovel_spec.cr b/spec/shovel_spec.cr
index a7dd230eeb..e5e1302838 100644
--- a/spec/shovel_spec.cr
+++ b/spec/shovel_spec.cr
@@ -258,7 +258,7 @@ describe LavinMQ::Shovel do
           x.publish_confirm "shovel me", "ap_q1"
           spawn shovel.run
           wait_for { shovel.running? }
-          sleep 0.1 # Give time for message to be shoveled
+          sleep 0.1.seconds # Give time for message to be shoveled
           s.vhosts["/"].queues["ap_q1"].message_count.should eq 0
           q2.get(no_ack: false).try(&.body_io.to_s).should eq "shovel me"
         end
@@ -644,7 +644,7 @@ describe LavinMQ::Shovel do
           props = AMQP::Client::Properties.new("text/plain", nil, headers)
           x.publish_confirm "shovel me", "ql_q1", props: props
           shovel.run
-          sleep 0.01
+          sleep 10.milliseconds
 
           # Check that we have sent one message successfully
           path.should eq "/pp"
diff --git a/spec/storage_spec.cr b/spec/storage_spec.cr
index 561adc1be2..4f70d17f72 100644
--- a/spec/storage_spec.cr
+++ b/spec/storage_spec.cr
@@ -33,7 +33,7 @@ describe LavinMQ::DurableQueue do
             queue = vhost.queues["corrupt_q"].as(LavinMQ::DurableQueue)
             q.publish_confirm "test message"
 
-            sleep 0.01
+            sleep 10.milliseconds
             bytes = "111111111aaaaauaoeuaoeu".to_slice
             queue.@msg_store.@segments.each_value do |mfile|
               File.open(mfile.path, "w+") do |f|
diff --git a/spec/stream_queue_spec.cr b/spec/stream_queue_spec.cr
index cb4ad7eb02..35aec89de1 100644
--- a/spec/stream_queue_spec.cr
+++ b/spec/stream_queue_spec.cr
@@ -112,7 +112,7 @@ describe LavinMQ::StreamQueue do
           q = ch.queue("stream-max-age", args: AMQP::Client::Arguments.new(args))
           data = Bytes.new(LavinMQ::Config.instance.segment_size)
           2.times { q.publish_confirm data }
-          sleep 1.1
+          sleep 1.1.seconds
           q.publish_confirm data
           q.message_count.should eq 1
         end
@@ -127,7 +127,7 @@ describe LavinMQ::StreamQueue do
           q = ch.queue("stream-max-age-policy", args: AMQP::Client::Arguments.new(args))
           data = Bytes.new(LavinMQ::Config.instance.segment_size)
           2.times { q.publish_confirm data }
-          sleep 1.1
+          sleep 1.1.seconds
           q.publish_confirm data
           q.message_count.should eq 1
         end
@@ -142,7 +142,7 @@ describe LavinMQ::StreamQueue do
           data = Bytes.new(LavinMQ::Config.instance.segment_size)
           2.times { q.publish_confirm data }
           q.message_count.should eq 2
-          sleep 1.1
+          sleep 1.1.seconds
           s.vhosts["/"].add_policy("max", "stream-max-age-policy", "queues", {"max-age" => JSON::Any.new("1s")}, 0i8)
           q.message_count.should eq 1
         end
diff --git a/spec/unix_server_spec.cr b/spec/unix_server_spec.cr
index 20f41ff03d..cf278aa8f4 100644
--- a/spec/unix_server_spec.cr
+++ b/spec/unix_server_spec.cr
@@ -4,7 +4,7 @@ describe LavinMQ::Server do
   describe "UNIX Sockets" do
     pending "can accept UNIX socket connections" do
       spawn { s.listen_unix("/tmp/lavinmq-spec/lavinmq.sock") }
-      sleep 0.01
+      sleep 10.milliseconds
       with_channel(host: "/tmp/lavinmq-spec/lavinmq.sock") do |ch|
         ch.should_not be_nil
       end
diff --git a/spec/upstream_spec.cr b/spec/upstream_spec.cr
index 95ca48108f..b86a7fc53c 100644
--- a/spec/upstream_spec.cr
+++ b/spec/upstream_spec.cr
@@ -246,7 +246,7 @@ describe LavinMQ::Federation::Upstream do
           end
           upstream_ex.publish_confirm "msg1", "rk1"
           msgs.receive.should eq "msg1"
-          sleep 0.01 # allow the downstream federation to ack the msg
+          sleep 10.milliseconds # allow the downstream federation to ack the msg
           upstream_vhost.connections.each do |conn|
             next unless conn.client_name.starts_with?("Federation link")
             conn.close
@@ -410,10 +410,10 @@ describe LavinMQ::Federation::Upstream do
           downstream_q.bind("downstream_ex", "after.link.#{i}")
           queues << downstream_q
         end
-        sleep 0.1
+        sleep 0.1.seconds
         upstream_q.bindings.size.should eq queues.size
         queues.each &.delete
-        sleep 0.01
+        sleep 10.milliseconds
         upstream_q.bindings.size.should eq 0
       end
     end
diff --git a/src/lavinmq/clustering/client.cr b/src/lavinmq/clustering/client.cr
index 2bb4a2a4d9..e088bbd9b7 100644
--- a/src/lavinmq/clustering/client.cr
+++ b/src/lavinmq/clustering/client.cr
@@ -81,7 +81,7 @@ module LavinMQ
           socket.try &.close
           break if @closed
           Log.info { "Disconnected from server #{host}:#{port} (#{ex}), retrying..." }
-          sleep 1
+          sleep 1.seconds
         end
       end
 
diff --git a/src/lavinmq/etcd.cr b/src/lavinmq/etcd.cr
index eb837dd084..3c3609b895 100644
--- a/src/lavinmq/etcd.cr
+++ b/src/lavinmq/etcd.cr
@@ -224,11 +224,11 @@ module LavinMQ
         rescue ex : Error
           Log.warn { "Service Unavailable at #{address}, #{ex.message}, retrying" }
           socket.close rescue nil
-          sleep 0.1
+          sleep 0.1.seconds
         rescue IO::Error
           Log.warn { "Lost connection to #{address}, retrying" }
           socket.close rescue nil
-          sleep 0.1
+          sleep 0.1.seconds
         ensure
           @connections.push({socket, address}) unless socket.closed?
         end
diff --git a/src/lavinmq/launcher.cr b/src/lavinmq/launcher.cr
index 4e170e6859..9ffb8e27d6 100644
--- a/src/lavinmq/launcher.cr
+++ b/src/lavinmq/launcher.cr
@@ -51,7 +51,7 @@ module LavinMQ
             GC.collect
           end
         else
-          sleep 30
+          sleep 30.seconds
           @data_dir_lock.try &.poll
           GC.collect
         end
diff --git a/src/lavinmq/queue/stream_queue.cr b/src/lavinmq/queue/stream_queue.cr
index 7fb74e20fe..54a8876a60 100644
--- a/src/lavinmq/queue/stream_queue.cr
+++ b/src/lavinmq/queue/stream_queue.cr
@@ -148,7 +148,7 @@ module LavinMQ
 
     private def unmap_and_remove_segments_loop
       until closed?
-        sleep 60
+        sleep 60.seconds
         unmap_and_remove_segments
       end
     end
diff --git a/src/lavinmq/rough_time.cr b/src/lavinmq/rough_time.cr
index 8bc00c54b7..f940464598 100644
--- a/src/lavinmq/rough_time.cr
+++ b/src/lavinmq/rough_time.cr
@@ -5,7 +5,7 @@ module RoughTime
 
   spawn(name: "RoughTime") do
     loop do
-      sleep 0.1
+      sleep 0.1.seconds
       @@utc = Time.utc
       @@unix_ms = @@utc.to_unix_ms // 100 * 100
       @@monotonic = Time.monotonic
diff --git a/src/lavinmq/shovel/shovel.cr b/src/lavinmq/shovel/shovel.cr
index 1fd6e4e592..e478cceb1e 100644
--- a/src/lavinmq/shovel/shovel.cr
+++ b/src/lavinmq/shovel/shovel.cr
@@ -9,7 +9,7 @@ module LavinMQ
     DEFAULT_ACK_MODE          = AckMode::OnConfirm
     DEFAULT_DELETE_AFTER      = DeleteAfter::Never
     DEFAULT_PREFETCH          = 1000_u16
-    DEFAULT_RECONNECT_DELAY   =        5
+    DEFAULT_RECONNECT_DELAY   = 5.seconds
     DEFAULT_BATCH_ACK_TIMEOUT = 3.seconds
 
     enum State
@@ -373,7 +373,7 @@ module LavinMQ
       getter name, vhost
 
       def initialize(@source : AMQPSource, @destination : Destination,
-                     @name : String, @vhost : VHost, @reconnect_delay = DEFAULT_RECONNECT_DELAY)
+                     @name : String, @vhost : VHost, @reconnect_delay : Time::Span = DEFAULT_RECONNECT_DELAY)
       end
 
       def state
@@ -427,7 +427,7 @@ module LavinMQ
       def exponential_reconnect_delay
         @retries += 1
         if @retries > RETRY_THRESHOLD
-          sleep Math.min(MAX_DELAY, @reconnect_delay ** (@retries - RETRY_THRESHOLD))
+          sleep Math.min(MAX_DELAY, @reconnect_delay.seconds ** (@retries - RETRY_THRESHOLD)).seconds
         else
           sleep @reconnect_delay
         end
diff --git a/src/lavinmq/shovel/shovel_store.cr b/src/lavinmq/shovel/shovel_store.cr
index 42bdb2c36f..f69f40bbb5 100644
--- a/src/lavinmq/shovel/shovel_store.cr
+++ b/src/lavinmq/shovel/shovel_store.cr
@@ -21,7 +21,7 @@ module LavinMQ
       delete_after = Shovel::DeleteAfter.parse?(delete_after_str) || Shovel::DEFAULT_DELETE_AFTER
       ack_mode_str = config["ack-mode"]?.try(&.as_s.delete("-")).to_s
       ack_mode = Shovel::AckMode.parse?(ack_mode_str) || Shovel::DEFAULT_ACK_MODE
-      reconnect_delay = config["reconnect-delay"]?.try &.as_i || Shovel::DEFAULT_RECONNECT_DELAY
+      reconnect_delay = config["reconnect-delay"]?.try &.as_i.seconds || Shovel::DEFAULT_RECONNECT_DELAY
       prefetch = config["src-prefetch-count"]?.try(&.as_i.to_u16) || Shovel::DEFAULT_PREFETCH
       src = Shovel::AMQPSource.new(name, parse_uris(config["src-uri"]),
         config["src-queue"]?.try &.as_s?,
diff --git a/src/lavinmq/vhost.cr b/src/lavinmq/vhost.cr
index f89d5d1831..9db3c96dfc 100644
--- a/src/lavinmq/vhost.cr
+++ b/src/lavinmq/vhost.cr
@@ -63,7 +63,7 @@ module LavinMQ
 
     private def check_consumer_timeouts_loop
       loop do
-        sleep Config.instance.consumer_timeout_loop_interval
+        sleep Config.instance.consumer_timeout_loop_interval.seconds
         return if @closed
         @connections.each do |c|
           c.channels.each_value do |ch|
@@ -457,7 +457,7 @@ module LavinMQ
       # wait up to 10s for clients to gracefully close
       100.times do
         break if @connections.empty?
-        sleep 0.1
+        sleep 0.1.seconds
       end
       # then force close the remaining (close tcp socket)
       @connections.each &.force_close
@@ -508,7 +508,7 @@ module LavinMQ
     private def load!
       load_definitions!
       spawn(name: "Load parameters") do
-        sleep 0.01
+        sleep 10.milliseconds
         next if @closed
         apply_parameters
         apply_policies
diff --git a/src/lavinmqperf.cr b/src/lavinmqperf.cr
index 77f3821791..0200417d99 100644
--- a/src/lavinmqperf.cr
+++ b/src/lavinmqperf.cr
@@ -183,7 +183,7 @@ class Throughput < Perf
       break if @stopped
       pubs_last = @pubs
       consumes_last = @consumes
-      sleep 1
+      sleep 1.seconds
       unless @quiet
         puts "Publish rate: #{@pubs - pubs_last} msgs/s Consume rate: #{@consumes - consumes_last} msgs/s"
       end
@@ -334,7 +334,7 @@ class Throughput < Perf
       break yield
     rescue ex : AMQP::Client::Error | IO::Error
       puts ex.message
-      sleep 1
+      sleep 1.seconds
     end
   ensure
     done.done