diff --git a/src/Microsoft.AspNet.Server.Kestrel/Http/SocketOutput.cs b/src/Microsoft.AspNet.Server.Kestrel/Http/SocketOutput.cs
index 5c890807b6..0eed51d7d3 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Http/SocketOutput.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Http/SocketOutput.cs
@@ -196,8 +196,8 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
                 }
 
                 // Now that the while loop has completed the following invariants should hold true:
-                Trace.Assert(_numBytesPreCompleted >= 0);
-                Trace.Assert(_numBytesPreCompleted <= _maxBytesPreCompleted);
+                Debug.Assert(_numBytesPreCompleted >= 0);
+                Debug.Assert(_numBytesPreCompleted <= _maxBytesPreCompleted);
             }
         }
 
diff --git a/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/MemoryPoolBlock2.cs b/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/MemoryPoolBlock2.cs
index bb7eb5758c..c0c9fae183 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/MemoryPoolBlock2.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/MemoryPoolBlock2.cs
@@ -77,6 +77,9 @@ namespace Microsoft.AspNet.Server.Kestrel.Infrastructure
 
         ~MemoryPoolBlock2()
         {
+            Debug.Assert(!_pinHandle.IsAllocated, "Ad-hoc memory block wasn't unpinned");
+            Debug.Assert(Slab == null || !Slab.IsActive, "Block being garbage collected instead of returned to pool");
+
             if (_pinHandle.IsAllocated)
             {
                 // if this is a one-time-use block, ensure that the GCHandle does not leak
diff --git a/src/Microsoft.AspNet.Server.Kestrel/Networking/UvMemory.cs b/src/Microsoft.AspNet.Server.Kestrel/Networking/UvMemory.cs
index 051218ffef..a8389c39a2 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Networking/UvMemory.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Networking/UvMemory.cs
@@ -77,9 +77,9 @@ namespace Microsoft.AspNet.Server.Kestrel.Networking
 
         public void Validate(bool closed = false)
         {
-            Trace.Assert(closed || !IsClosed, "Handle is closed");
-            Trace.Assert(!IsInvalid, "Handle is invalid");
-            Trace.Assert(_threadId == Thread.CurrentThread.ManagedThreadId, "ThreadId is incorrect");
+            Debug.Assert(closed || !IsClosed, "Handle is closed");
+            Debug.Assert(!IsInvalid, "Handle is invalid");
+            Debug.Assert(_threadId == Thread.CurrentThread.ManagedThreadId, "ThreadId is incorrect");
         }
 
         unsafe public static THandle FromIntPtr<THandle>(IntPtr handle)