diff --git a/SteamKit2/SteamKit2/Steam/CMClient.cs b/SteamKit2/SteamKit2/Steam/CMClient.cs
index d4c9e633f..afdb5bf73 100644
--- a/SteamKit2/SteamKit2/Steam/CMClient.cs
+++ b/SteamKit2/SteamKit2/Steam/CMClient.cs
@@ -142,10 +142,12 @@ public CMClient( SteamConfiguration configuration, string identifier )
 
             ID = identifier;
 
-            heartBeatFunc = new ScheduledFunction( () =>
-            {
-                Send( new ClientMsgProtobuf<CMsgClientHeartBeat>( EMsg.ClientHeartBeat ) );
-            } );
+            heartBeatFunc = new ScheduledFunction(
+                configuration.TimeProvider,
+                () =>
+                {
+                    Send( new ClientMsgProtobuf<CMsgClientHeartBeat>( EMsg.ClientHeartBeat ) );
+                } );
         }
 
         /// <summary>
diff --git a/SteamKit2/SteamKit2/Steam/SteamClient/AsyncJobManager.cs b/SteamKit2/SteamKit2/Steam/SteamClient/AsyncJobManager.cs
index 714ace6e5..74f27421d 100644
--- a/SteamKit2/SteamKit2/Steam/SteamClient/AsyncJobManager.cs
+++ b/SteamKit2/SteamKit2/Steam/SteamClient/AsyncJobManager.cs
@@ -8,11 +8,11 @@ class AsyncJobManager
         internal ConcurrentDictionary<JobID, AsyncJob> asyncJobs;
         internal ScheduledFunction jobTimeoutFunc;
 
-        public AsyncJobManager()
+        public AsyncJobManager( TimeProvider timeProvider )
         {
             asyncJobs = new ConcurrentDictionary<JobID, AsyncJob>();
 
-            jobTimeoutFunc = new ScheduledFunction( CancelTimedoutJobs, TimeSpan.FromSeconds( 1 ) );
+            jobTimeoutFunc = new ScheduledFunction( timeProvider, CancelTimedoutJobs, TimeSpan.FromSeconds( 1 ) );
         }
 
 
diff --git a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/ISteamConfigurationBuilder.cs b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/ISteamConfigurationBuilder.cs
index 25023cbfe..737191874 100644
--- a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/ISteamConfigurationBuilder.cs
+++ b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/ISteamConfigurationBuilder.cs
@@ -72,6 +72,14 @@ public interface ISteamConfigurationBuilder
         /// <returns>A builder with modified configuration.</returns>
         ISteamConfigurationBuilder WithServerListProvider(IServerListProvider provider);
 
+        /// <summary>
+        /// Configures the <see cref="TimeProvider"/> for this <see cref="SteamConfiguration" />.
+        /// This can be changed for testing and diagnostic purposes.
+        /// </summary>
+        /// <param name="timeProvider">The time provider to use.</param>
+        /// <returns>A builder with modified configuration.</returns>
+        ISteamConfigurationBuilder WithTimeProvider(TimeProvider timeProvider);
+
         /// <summary>
         /// Configures the Universe that this <see cref="SteamConfiguration" /> belongs to.
         /// </summary>
diff --git a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfiguration.cs b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfiguration.cs
index e16b61a22..1e3be4a82 100644
--- a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfiguration.cs
+++ b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfiguration.cs
@@ -93,6 +93,12 @@ internal static SteamConfiguration CreateDefault()
         /// </summary>
         public IServerListProvider ServerListProvider => state.ServerListProvider;
 
+        /// <summary>
+        /// The <see cref="TimeProvider"/> used to control the flow of time.
+        /// This can be changed for testing and diagnostic purposes.
+        /// </summary>
+        public TimeProvider TimeProvider => state.TimeProvider;
+
         /// <summary>
         /// The Universe to connect to. This should always be <see cref="EUniverse.Public"/> unless
         /// you work at Valve and are using this internally. If this is you, hello there.
@@ -106,7 +112,7 @@ internal static SteamConfiguration CreateDefault()
         public Uri WebAPIBaseAddress => state.WebAPIBaseAddress;
 
         /// <summary>
-        /// An  API key to be used for authorized requests.
+        /// An API key to be used for authorized requests.
         /// Keys can be obtained from https://steamcommunity.com/dev or the Steamworks Partner site.
         /// </summary>
         public string WebAPIKey => state.WebAPIKey;
diff --git a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationBuilder.cs b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationBuilder.cs
index eb23cc202..34252f35c 100644
--- a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationBuilder.cs
+++ b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationBuilder.cs
@@ -39,6 +39,8 @@ public static SteamConfigurationState CreateDefaultState()
 
                 ServerListProvider = new MemoryServerListProvider(),
 
+                TimeProvider = TimeProvider.System,
+
                 Universe = EUniverse.Public,
 
                 WebAPIBaseAddress = WebAPI.DefaultBaseAddress
@@ -98,6 +100,13 @@ public ISteamConfigurationBuilder WithServerListProvider(IServerListProvider pro
             return this;
         }
 
+        public ISteamConfigurationBuilder WithTimeProvider(TimeProvider timeProvider)
+        {
+            ArgumentNullException.ThrowIfNull(timeProvider);
+            state.TimeProvider = timeProvider;
+            return this;
+        }
+
         public ISteamConfigurationBuilder WithUniverse(EUniverse universe)
         {
             state.Universe = universe;
diff --git a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationState.cs b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationState.cs
index da60c2e5f..4ba946d19 100644
--- a/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationState.cs
+++ b/SteamKit2/SteamKit2/Steam/SteamClient/Configuration/SteamConfigurationState.cs
@@ -19,6 +19,7 @@ struct SteamConfigurationState
         public IMachineInfoProvider MachineInfoProvider;
         public ProtocolTypes ProtocolTypes;
         public IServerListProvider ServerListProvider;
+        public TimeProvider TimeProvider;
         public EUniverse Universe;
         public Uri WebAPIBaseAddress;
         public string WebAPIKey;
diff --git a/SteamKit2/SteamKit2/Steam/SteamClient/SteamClient.cs b/SteamKit2/SteamKit2/Steam/SteamClient/SteamClient.cs
index 49faf017e..1b2009c32 100644
--- a/SteamKit2/SteamKit2/Steam/SteamClient/SteamClient.cs
+++ b/SteamKit2/SteamKit2/Steam/SteamClient/SteamClient.cs
@@ -106,7 +106,7 @@ public SteamClient( SteamConfiguration configuration, string identifier )
                 this.processStartTime = process.StartTime;
             }
 
-            jobManager = new AsyncJobManager();
+            jobManager = new AsyncJobManager( configuration.TimeProvider );
         }
 
 
diff --git a/SteamKit2/SteamKit2/Util/ScheduledFunction.cs b/SteamKit2/SteamKit2/Util/ScheduledFunction.cs
index 72369ec9b..ea79615ec 100644
--- a/SteamKit2/SteamKit2/Util/ScheduledFunction.cs
+++ b/SteamKit2/SteamKit2/Util/ScheduledFunction.cs
@@ -17,19 +17,19 @@ class ScheduledFunction
         Action func;
 
         bool bStarted;
-        Timer timer;
+        ITimer timer;
 
-        public ScheduledFunction( Action func )
-            : this( func, TimeSpan.FromMilliseconds( -1 ) )
+        public ScheduledFunction( TimeProvider timeProvider, Action func )
+            : this( timeProvider, func, TimeSpan.FromMilliseconds( -1 ) )
         {
         }
 
-        public ScheduledFunction( Action func, TimeSpan delay )
+        public ScheduledFunction( TimeProvider timeProvider, Action func, TimeSpan delay )
         {
             this.func = func;
             this.Delay = delay;
 
-            timer = new Timer( Tick, null, TimeSpan.FromMilliseconds( -1 ), delay );
+            timer = timeProvider.CreateTimer( Tick, null, TimeSpan.FromMilliseconds( -1 ), delay );
         }
         ~ScheduledFunction()
         {
diff --git a/SteamKit2/Tests/SteamConfigurationFacts.cs b/SteamKit2/Tests/SteamConfigurationFacts.cs
index 9a6c08d7d..d9668fa1c 100644
--- a/SteamKit2/Tests/SteamConfigurationFacts.cs
+++ b/SteamKit2/Tests/SteamConfigurationFacts.cs
@@ -88,6 +88,12 @@ public void PublicUniverse()
             Assert.Equal(EUniverse.Public, configuration.Universe);
         }
 
+        [Fact]
+        public void TimeProviderIsSystemTime()
+        {
+            Assert.Equal(TimeProvider.System, configuration.TimeProvider);
+        }
+
         [Fact]
         public void WebAPIAddress()
         {
@@ -114,6 +120,7 @@ public SteamConfigurationConfiguredObjectFacts()
                  .WithMachineInfoProvider(new CustomMachineInfoProvider())
                  .WithProtocolTypes(ProtocolTypes.WebSocket | ProtocolTypes.Udp)
                  .WithServerListProvider(new CustomServerListProvider())
+                 .WithTimeProvider(new CustomTimeProvider())
                  .WithUniverse(EUniverse.Internal)
                  .WithWebAPIBaseAddress(new Uri("http://foo.bar.com/api/"))
                  .WithWebAPIKey("T0PS3kR1t"));
@@ -177,6 +184,12 @@ public void ProtocolsAreConfigured()
             Assert.Equal(ProtocolTypes.WebSocket | ProtocolTypes.Udp, configuration.ProtocolTypes);
         }
 
+        [Fact]
+        public void TimeProviderIsConfigured()
+        {
+            Assert.IsType<CustomTimeProvider>(configuration.TimeProvider);
+        }
+
         [Fact]
         public void UniverseIsConfigured()
         {
@@ -213,5 +226,9 @@ Task<IEnumerable<ServerRecord>> IServerListProvider.FetchServerListAsync()
             Task IServerListProvider.UpdateServerListAsync(IEnumerable<ServerRecord> endpoints)
                 => throw new NotImplementedException();
         }
+
+        class CustomTimeProvider : TimeProvider
+        {
+        }
     }
 }