diff --git a/Src/FluentAssertions/AssertionExtensions.cs b/Src/FluentAssertions/AssertionExtensions.cs
index a651e486b3..300a86039a 100644
--- a/Src/FluentAssertions/AssertionExtensions.cs
+++ b/Src/FluentAssertions/AssertionExtensions.cs
@@ -1050,9 +1050,9 @@ public static void Should<TAssertions>(this SimpleTimeSpanAssertions<TAssertions
         InvalidShouldCall();
     }
 
-    /// <inheritdoc cref="Should{T}(System.Threading.Tasks.TaskCompletionSource{T})" />
+    /// <inheritdoc cref="Should(ExecutionTimeAssertions)" />
     [Obsolete("You are asserting the 'AndConstraint' itself. Remove the 'Should()' method directly following 'And'", error: true)]
-    public static void Should<TSubject>(this TaskCompletionSourceAssertions<TSubject> _)
+    public static void Should(this TaskCompletionSourceAssertionsBase _)
     {
         InvalidShouldCall();
     }
@@ -1089,17 +1089,6 @@ public static void Should<TAssertions>(this DateTimeOffsetRangeAssertions<TAsser
         InvalidShouldCall();
     }
 
-#if  NET6_0_OR_GREATER
-
-    /// <inheritdoc cref="Should(System.Threading.Tasks.TaskCompletionSource)" />
-    [Obsolete("You are asserting the 'AndConstraint' itself. Remove the 'Should()' method directly following 'And'", error: true)]
-    public static void Should(this TaskCompletionSourceAssertions _)
-    {
-        InvalidShouldCall();
-    }
-
-#endif
-
     [DoesNotReturn]
     private static void InvalidShouldCall()
     {
diff --git a/Src/FluentAssertions/Specialized/TaskCompletionSourceAssertions.cs b/Src/FluentAssertions/Specialized/TaskCompletionSourceAssertions.cs
index 0ea3a39e34..3adc8892a0 100644
--- a/Src/FluentAssertions/Specialized/TaskCompletionSourceAssertions.cs
+++ b/Src/FluentAssertions/Specialized/TaskCompletionSourceAssertions.cs
@@ -26,7 +26,7 @@ public TaskCompletionSourceAssertions(TaskCompletionSource tcs, IClock clock)
     }
 
     /// <summary>
-    /// Asserts that the <see cref="Task"/> of the current <see cref="TaskCompletionSource{T}"/> will complete within the specified time.
+    /// Asserts that the <see cref="Task"/> of the current <see cref="TaskCompletionSource"/> will complete within the specified time.
     /// </summary>
     /// <param name="timeSpan">The allowed time span for the operation.</param>
     /// <param name="because">
@@ -57,7 +57,7 @@ public TaskCompletionSourceAssertions(TaskCompletionSource tcs, IClock clock)
     }
 
     /// <summary>
-    /// Asserts that the <see cref="Task"/> of the current <see cref="TaskCompletionSource{T}"/> will not complete within the specified time.
+    /// Asserts that the <see cref="Task"/> of the current <see cref="TaskCompletionSource"/> will not complete within the specified time.
     /// </summary>
     /// <param name="timeSpan">The time span to wait for the operation.</param>
     /// <param name="because">
@@ -189,7 +189,7 @@ protected TaskCompletionSourceAssertionsBase(IClock clock)
     /// <summary>
     ///     Monitors the specified task whether it completes withing the remaining time span.
     /// </summary>
-    protected async Task<bool> CompletesWithinTimeoutAsync(Task target, TimeSpan remainingTime)
+    private protected async Task<bool> CompletesWithinTimeoutAsync(Task target, TimeSpan remainingTime)
     {
         using var timeoutCancellationTokenSource = new CancellationTokenSource();
 
diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt
index f2d2ba526e..f4c9cab2a9 100644
--- a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt
+++ b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt
@@ -43,6 +43,9 @@ namespace FluentAssertions
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
         public static void Should(this FluentAssertions.Specialized.ExecutionTimeAssertions _) { }
+        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
+            "ly following \'And\'", true)]
+        public static void Should(this FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase _) { }
         public static FluentAssertions.Types.MethodInfoSelectorAssertions Should(this FluentAssertions.Types.MethodInfoSelector methodSelector) { }
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
@@ -135,9 +138,6 @@ namespace FluentAssertions
             "ly following \'And\'", true)]
         public static void Should<TAssertions>(this FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> _)
             where TAssertions : FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> { }
-        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
-            "ly following \'And\'", true)]
-        public static void Should<TSubject>(this FluentAssertions.Specialized.TaskCompletionSourceAssertions<TSubject> _) { }
         public static FluentAssertions.Collections.GenericCollectionAssertions<T> Should<T>(this System.Collections.Generic.IEnumerable<T> actualValue) { }
         public static FluentAssertions.Specialized.GenericAsyncFunctionAssertions<T> Should<T>(this System.Func<System.Threading.Tasks.Task<T>> action) { }
         public static FluentAssertions.Specialized.FunctionAssertions<T> Should<T>(this System.Func<T> func) { }
@@ -2348,13 +2348,17 @@ namespace FluentAssertions.Specialized
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor) { }
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor, FluentAssertions.Common.IClock clock) { }
     }
-    public class TaskCompletionSourceAssertions<T>
+    public class TaskCompletionSourceAssertionsBase
+    {
+        protected TaskCompletionSourceAssertionsBase(FluentAssertions.Common.IClock clock) { }
+        public override bool Equals(object obj) { }
+    }
+    public class TaskCompletionSourceAssertions<T> : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs, FluentAssertions.Common.IClock clock) { }
         public System.Threading.Tasks.Task<FluentAssertions.AndWhichConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>, T>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
-        public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
 }
 namespace FluentAssertions.Streams
diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt
index 72b667097b..b2fc685a80 100644
--- a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt
+++ b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt
@@ -43,6 +43,9 @@ namespace FluentAssertions
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
         public static void Should(this FluentAssertions.Specialized.ExecutionTimeAssertions _) { }
+        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
+            "ly following \'And\'", true)]
+        public static void Should(this FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase _) { }
         public static FluentAssertions.Types.MethodInfoSelectorAssertions Should(this FluentAssertions.Types.MethodInfoSelector methodSelector) { }
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
@@ -148,9 +151,6 @@ namespace FluentAssertions
             "ly following \'And\'", true)]
         public static void Should<TAssertions>(this FluentAssertions.Primitives.TimeOnlyAssertions<TAssertions> _)
             where TAssertions : FluentAssertions.Primitives.TimeOnlyAssertions<TAssertions> { }
-        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
-            "ly following \'And\'", true)]
-        public static void Should<TSubject>(this FluentAssertions.Specialized.TaskCompletionSourceAssertions<TSubject> _) { }
         public static FluentAssertions.Collections.GenericCollectionAssertions<T> Should<T>(this System.Collections.Generic.IEnumerable<T> actualValue) { }
         public static FluentAssertions.Specialized.GenericAsyncFunctionAssertions<T> Should<T>(this System.Func<System.Threading.Tasks.Task<T>> action) { }
         public static FluentAssertions.Specialized.FunctionAssertions<T> Should<T>(this System.Func<T> func) { }
@@ -2467,21 +2467,24 @@ namespace FluentAssertions.Specialized
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor) { }
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor, FluentAssertions.Common.IClock clock) { }
     }
-    public class TaskCompletionSourceAssertions
+    public class TaskCompletionSourceAssertions : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource tcs, FluentAssertions.Common.IClock clock) { }
-        public System.Threading.Tasks.Task CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+    }
+    public class TaskCompletionSourceAssertionsBase
+    {
+        protected TaskCompletionSourceAssertionsBase(FluentAssertions.Common.IClock clock) { }
         public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
-    public class TaskCompletionSourceAssertions<T>
+    public class TaskCompletionSourceAssertions<T> : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs, FluentAssertions.Common.IClock clock) { }
         public System.Threading.Tasks.Task<FluentAssertions.AndWhichConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>, T>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
-        public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
 }
 namespace FluentAssertions.Streams
diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt
index 9e06dba6fd..326829c95c 100644
--- a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt
+++ b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt
@@ -43,6 +43,9 @@ namespace FluentAssertions
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
         public static void Should(this FluentAssertions.Specialized.ExecutionTimeAssertions _) { }
+        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
+            "ly following \'And\'", true)]
+        public static void Should(this FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase _) { }
         public static FluentAssertions.Types.MethodInfoSelectorAssertions Should(this FluentAssertions.Types.MethodInfoSelector methodSelector) { }
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
@@ -135,9 +138,6 @@ namespace FluentAssertions
             "ly following \'And\'", true)]
         public static void Should<TAssertions>(this FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> _)
             where TAssertions : FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> { }
-        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
-            "ly following \'And\'", true)]
-        public static void Should<TSubject>(this FluentAssertions.Specialized.TaskCompletionSourceAssertions<TSubject> _) { }
         public static FluentAssertions.Collections.GenericCollectionAssertions<T> Should<T>(this System.Collections.Generic.IEnumerable<T> actualValue) { }
         public static FluentAssertions.Specialized.GenericAsyncFunctionAssertions<T> Should<T>(this System.Func<System.Threading.Tasks.Task<T>> action) { }
         public static FluentAssertions.Specialized.FunctionAssertions<T> Should<T>(this System.Func<T> func) { }
@@ -2348,13 +2348,17 @@ namespace FluentAssertions.Specialized
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor) { }
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor, FluentAssertions.Common.IClock clock) { }
     }
-    public class TaskCompletionSourceAssertions<T>
+    public class TaskCompletionSourceAssertionsBase
+    {
+        protected TaskCompletionSourceAssertionsBase(FluentAssertions.Common.IClock clock) { }
+        public override bool Equals(object obj) { }
+    }
+    public class TaskCompletionSourceAssertions<T> : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs, FluentAssertions.Common.IClock clock) { }
         public System.Threading.Tasks.Task<FluentAssertions.AndWhichConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>, T>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
-        public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
 }
 namespace FluentAssertions.Streams
diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt
index 26f5978a06..3cf876407b 100644
--- a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt
+++ b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt
@@ -43,6 +43,9 @@ namespace FluentAssertions
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
         public static void Should(this FluentAssertions.Specialized.ExecutionTimeAssertions _) { }
+        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
+            "ly following \'And\'", true)]
+        public static void Should(this FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase _) { }
         public static FluentAssertions.Types.MethodInfoSelectorAssertions Should(this FluentAssertions.Types.MethodInfoSelector methodSelector) { }
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
@@ -135,9 +138,6 @@ namespace FluentAssertions
             "ly following \'And\'", true)]
         public static void Should<TAssertions>(this FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> _)
             where TAssertions : FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> { }
-        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
-            "ly following \'And\'", true)]
-        public static void Should<TSubject>(this FluentAssertions.Specialized.TaskCompletionSourceAssertions<TSubject> _) { }
         public static FluentAssertions.Collections.GenericCollectionAssertions<T> Should<T>(this System.Collections.Generic.IEnumerable<T> actualValue) { }
         public static FluentAssertions.Specialized.GenericAsyncFunctionAssertions<T> Should<T>(this System.Func<System.Threading.Tasks.Task<T>> action) { }
         public static FluentAssertions.Specialized.FunctionAssertions<T> Should<T>(this System.Func<T> func) { }
@@ -2348,13 +2348,17 @@ namespace FluentAssertions.Specialized
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor) { }
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor, FluentAssertions.Common.IClock clock) { }
     }
-    public class TaskCompletionSourceAssertions<T>
+    public class TaskCompletionSourceAssertionsBase
+    {
+        protected TaskCompletionSourceAssertionsBase(FluentAssertions.Common.IClock clock) { }
+        public override bool Equals(object obj) { }
+    }
+    public class TaskCompletionSourceAssertions<T> : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs, FluentAssertions.Common.IClock clock) { }
         public System.Threading.Tasks.Task<FluentAssertions.AndWhichConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>, T>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
-        public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
 }
 namespace FluentAssertions.Streams
diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt
index d64dbc6ef5..37237ba2d8 100644
--- a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt
+++ b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt
@@ -42,6 +42,9 @@ namespace FluentAssertions
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
         public static void Should(this FluentAssertions.Specialized.ExecutionTimeAssertions _) { }
+        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
+            "ly following \'And\'", true)]
+        public static void Should(this FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase _) { }
         public static FluentAssertions.Types.MethodInfoSelectorAssertions Should(this FluentAssertions.Types.MethodInfoSelector methodSelector) { }
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
@@ -134,9 +137,6 @@ namespace FluentAssertions
             "ly following \'And\'", true)]
         public static void Should<TAssertions>(this FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> _)
             where TAssertions : FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> { }
-        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
-            "ly following \'And\'", true)]
-        public static void Should<TSubject>(this FluentAssertions.Specialized.TaskCompletionSourceAssertions<TSubject> _) { }
         public static FluentAssertions.Collections.GenericCollectionAssertions<T> Should<T>(this System.Collections.Generic.IEnumerable<T> actualValue) { }
         public static FluentAssertions.Specialized.GenericAsyncFunctionAssertions<T> Should<T>(this System.Func<System.Threading.Tasks.Task<T>> action) { }
         public static FluentAssertions.Specialized.FunctionAssertions<T> Should<T>(this System.Func<T> func) { }
@@ -2300,13 +2300,17 @@ namespace FluentAssertions.Specialized
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor) { }
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor, FluentAssertions.Common.IClock clock) { }
     }
-    public class TaskCompletionSourceAssertions<T>
+    public class TaskCompletionSourceAssertionsBase
+    {
+        protected TaskCompletionSourceAssertionsBase(FluentAssertions.Common.IClock clock) { }
+        public override bool Equals(object obj) { }
+    }
+    public class TaskCompletionSourceAssertions<T> : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs, FluentAssertions.Common.IClock clock) { }
         public System.Threading.Tasks.Task<FluentAssertions.AndWhichConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>, T>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
-        public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
 }
 namespace FluentAssertions.Streams
diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt
index fdddf3faf8..7cb0960b6b 100644
--- a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt
+++ b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt
@@ -43,6 +43,9 @@ namespace FluentAssertions
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
         public static void Should(this FluentAssertions.Specialized.ExecutionTimeAssertions _) { }
+        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
+            "ly following \'And\'", true)]
+        public static void Should(this FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase _) { }
         public static FluentAssertions.Types.MethodInfoSelectorAssertions Should(this FluentAssertions.Types.MethodInfoSelector methodSelector) { }
         [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
             "ly following \'And\'", true)]
@@ -135,9 +138,6 @@ namespace FluentAssertions
             "ly following \'And\'", true)]
         public static void Should<TAssertions>(this FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> _)
             where TAssertions : FluentAssertions.Primitives.SimpleTimeSpanAssertions<TAssertions> { }
-        [System.Obsolete("You are asserting the \'AndConstraint\' itself. Remove the \'Should()\' method direct" +
-            "ly following \'And\'", true)]
-        public static void Should<TSubject>(this FluentAssertions.Specialized.TaskCompletionSourceAssertions<TSubject> _) { }
         public static FluentAssertions.Collections.GenericCollectionAssertions<T> Should<T>(this System.Collections.Generic.IEnumerable<T> actualValue) { }
         public static FluentAssertions.Specialized.GenericAsyncFunctionAssertions<T> Should<T>(this System.Func<System.Threading.Tasks.Task<T>> action) { }
         public static FluentAssertions.Specialized.FunctionAssertions<T> Should<T>(this System.Func<T> func) { }
@@ -2348,13 +2348,17 @@ namespace FluentAssertions.Specialized
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor) { }
         public NonGenericAsyncFunctionAssertions(System.Func<System.Threading.Tasks.Task> subject, FluentAssertions.Specialized.IExtractExceptions extractor, FluentAssertions.Common.IClock clock) { }
     }
-    public class TaskCompletionSourceAssertions<T>
+    public class TaskCompletionSourceAssertionsBase
+    {
+        protected TaskCompletionSourceAssertionsBase(FluentAssertions.Common.IClock clock) { }
+        public override bool Equals(object obj) { }
+    }
+    public class TaskCompletionSourceAssertions<T> : FluentAssertions.Specialized.TaskCompletionSourceAssertionsBase
     {
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs) { }
         public TaskCompletionSourceAssertions(System.Threading.Tasks.TaskCompletionSource<T> tcs, FluentAssertions.Common.IClock clock) { }
         public System.Threading.Tasks.Task<FluentAssertions.AndWhichConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>, T>> CompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
-        public override bool Equals(object obj) { }
-        public System.Threading.Tasks.Task NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
+        public System.Threading.Tasks.Task<FluentAssertions.AndConstraint<FluentAssertions.Specialized.TaskCompletionSourceAssertions<T>>> NotCompleteWithinAsync(System.TimeSpan timeSpan, string because = "", params object[] becauseArgs) { }
     }
 }
 namespace FluentAssertions.Streams
diff --git a/Tests/FluentAssertions.Specs/AssertionExtensionsSpecs.cs b/Tests/FluentAssertions.Specs/AssertionExtensionsSpecs.cs
index 920d89afe5..ef6d97af10 100644
--- a/Tests/FluentAssertions.Specs/AssertionExtensionsSpecs.cs
+++ b/Tests/FluentAssertions.Specs/AssertionExtensionsSpecs.cs
@@ -56,7 +56,6 @@ private static bool OverridesEquals(Type t)
 #if NET6_0_OR_GREATER
         new object[] { new DateOnlyAssertions<DateOnlyAssertions>(default) },
         new object[] { new TimeOnlyAssertions<TimeOnlyAssertions>(default) },
-        new object[] { new TaskCompletionSourceAssertions<int>(default) }
 #endif
     };
 
@@ -84,13 +83,12 @@ public void Guarding_equals_throws(object obj)
     [InlineData(typeof(NumericAssertions<int, NumericAssertions<int>>))]
     [InlineData(typeof(PropertyInfoSelectorAssertions))]
     [InlineData(typeof(SimpleTimeSpanAssertions<SimpleTimeSpanAssertions>))]
-    [InlineData(typeof(TaskCompletionSourceAssertions<int>))]
+    [InlineData(typeof(TaskCompletionSourceAssertionsBase))]
     [InlineData(typeof(TypeSelectorAssertions))]
     [InlineData(typeof(EnumAssertions<StringComparison, EnumAssertions<StringComparison>>))]
 #if NET6_0_OR_GREATER
     [InlineData(typeof(DateOnlyAssertions<DateOnlyAssertions>))]
     [InlineData(typeof(TimeOnlyAssertions<TimeOnlyAssertions>))]
-    [InlineData(typeof(TaskCompletionSourceAssertions))]
 #endif
     public void Fake_should_method_throws(Type type)
     {
@@ -136,11 +134,13 @@ public void Should_methods_have_a_matching_overload_to_guard_against_chaining_an
             .Distinct()
             .Concat(new[]
             {
+                // @jnyrup: DateTimeRangeAssertions and DateTimeOffsetRangeAssertions are manually added here,
+                // because they expose AndConstraints,
+                // and hence should have a guarding Should(DateTimeRangeAssertions _) overloads,
+                // but they do not have a regular Should() overload,
+                // as they are always constructed through the fluent API.
                 typeof(DateTimeRangeAssertions<>),
                 typeof(DateTimeOffsetRangeAssertions<>),
-#if NET6_0_OR_GREATER
-                typeof(TaskCompletionSourceAssertions),
-#endif
             })
             .ToList();