diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Condition.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Condition.cs
index 70843a3b940fc..ceb60edb12e3f 100644
--- a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Condition.cs
+++ b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Condition.cs
@@ -89,7 +89,9 @@ private unsafe void RemoveWaiter(Waiter waiter)
 
         public Condition(Lock @lock)
         {
+#pragma warning disable CS9216 // A value of type 'System.Threading.Lock' converted to a different type will use likely unintended monitor-based locking in 'lock' statement.
             ArgumentNullException.ThrowIfNull(@lock);
+#pragma warning restore CS9216
             _lock = @lock;
         }
 
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/SyncTable.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/SyncTable.cs
index 02d7b4167ca6b..bdbf6ed752e6c 100644
--- a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/SyncTable.cs
+++ b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/SyncTable.cs
@@ -140,7 +140,7 @@ public static unsafe int AssignEntry(object obj, int* pHeader)
 
                     // Found a free entry to assign
                     Debug.Assert(!entry.Owner.IsAllocated);
-                    Debug.Assert(entry.Lock == null);
+                    Debug.Assert(entry.Lock is null);
                     Debug.Assert(entry.HashCode == 0);
 
                     // Set up the new entry.  We should not fail after this point.
diff --git a/src/libraries/System.Private.CoreLib/src/System/Threading/Lock.cs b/src/libraries/System.Private.CoreLib/src/System/Threading/Lock.cs
index 056ff96d41b1e..4828a6dd2b0e5 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Threading/Lock.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Threading/Lock.cs
@@ -120,7 +120,7 @@ internal Scope(Lock lockObj, ThreadId currentThreadId)
             public void Dispose()
             {
                 Lock? lockObj = _lockObj;
-                if (lockObj != null)
+                if (lockObj is not null)
                 {
                     _lockObj = null;
                     lockObj.Exit(_currentThreadId);