diff --git a/lib/ferrum/browser/process.rb b/lib/ferrum/browser/process.rb
index 7ca321ef..079f0439 100644
--- a/lib/ferrum/browser/process.rb
+++ b/lib/ferrum/browser/process.rb
@@ -16,7 +16,6 @@ module Ferrum
   class Browser
     class Process
       KILL_TIMEOUT = 2
-      WAIT_KILLED = 0.05
 
       attr_reader :host, :port, :ws_url, :pid, :command,
                   :default_user_agent, :browser_version, :protocol_version,
@@ -38,7 +37,7 @@ def self.process_killer(pid)
             ::Process.kill("USR1", pid)
             start = Utils::ElapsedTime.monotonic_time
             while ::Process.wait(pid, ::Process::WNOHANG).nil?
-              sleep(WAIT_KILLED)
+              ::Thread.pass
               next unless Utils::ElapsedTime.timeout?(start, KILL_TIMEOUT)
 
               ::Process.kill("KILL", pid)
diff --git a/lib/ferrum/network.rb b/lib/ferrum/network.rb
index 6d8c2c31..b88ec0fa 100644
--- a/lib/ferrum/network.rb
+++ b/lib/ferrum/network.rb
@@ -46,9 +46,6 @@ def initialize(page)
     # @param [Integer] connections
     #   how many connections are allowed for network to be idling,
     #
-    # @param [Float] duration
-    #   Sleep for given amount of time and check again.
-    #
     # @param [Float] timeout
     #   During what time we try to check idle.
     #
@@ -59,13 +56,13 @@ def initialize(page)
     #   browser.at_xpath("//a[text() = 'No UI changes button']").click
     #   browser.network.wait_for_idle # => false
     #
-    def wait_for_idle(connections: 0, duration: 0.05, timeout: @page.timeout)
+    def wait_for_idle(connections: 0, timeout: @page.timeout)
       start = Utils::ElapsedTime.monotonic_time
 
       until idle?(connections)
         return false if Utils::ElapsedTime.timeout?(start, timeout)
 
-        sleep(duration)
+        ::Thread.pass
       end
 
       true
diff --git a/lib/ferrum/utils/attempt.rb b/lib/ferrum/utils/attempt.rb
index 334b7cc6..e969ad47 100644
--- a/lib/ferrum/utils/attempt.rb
+++ b/lib/ferrum/utils/attempt.rb
@@ -13,6 +13,8 @@ def with_retry(errors:, max:, wait:)
 
         attempts += 1
         sleep(wait)
+
+        ::Thread.pass
         retry
       end
     end
diff --git a/lib/ferrum/utils/event.rb b/lib/ferrum/utils/event.rb
index cbd5bcea..d65fc35b 100644
--- a/lib/ferrum/utils/event.rb
+++ b/lib/ferrum/utils/event.rb
@@ -14,6 +14,20 @@ def reset
           @iteration
         end
       end
+
+      def wait(timeout)
+        synchronize do
+          unless @set
+            iteration = @iteration
+            ns_wait_until(timeout) do
+              iteration < @iteration || @set
+              ::Thread.pass
+            end
+          else
+            true
+          end
+        end
+      end
     end
   end
 end