diff --git a/src/runtime/Finalizer.cs b/src/runtime/Finalizer.cs
index e796cacd1..f4b465ecb 100644
--- a/src/runtime/Finalizer.cs
+++ b/src/runtime/Finalizer.cs
@@ -106,6 +106,7 @@ internal IncorrectRefCountException(IntPtr ptr)
 
         #endregion
 
+        [ForbidPythonThreads]
         public void Collect() => this.DisposeAll();
 
         internal void ThrottledCollect()
diff --git a/src/runtime/Native/NewReference.cs b/src/runtime/Native/NewReference.cs
index 25145fc4f..f7a030818 100644
--- a/src/runtime/Native/NewReference.cs
+++ b/src/runtime/Native/NewReference.cs
@@ -47,7 +47,7 @@ public PyObject MoveToPyObject()
         /// </summary>
         public NewReference Move()
         {
-            var result = new NewReference(this);
+            var result = DangerousFromPointer(this.DangerousGetAddress());
             this.pointer = default;
             return result;
         }
diff --git a/src/runtime/Runtime.cs b/src/runtime/Runtime.cs
index 20bef23d4..88a8ed173 100644
--- a/src/runtime/Runtime.cs
+++ b/src/runtime/Runtime.cs
@@ -359,6 +359,7 @@ static bool TryCollectingGarbage(int runs, bool forceBreakLoops)
         /// </summary>
         /// <param name="runs">Total number of GC loops to run</param>
         /// <returns><c>true</c> if a steady state was reached upon the requested number of tries (e.g. on the last try no objects were collected).</returns>
+        [ForbidPythonThreads]
         public static bool TryCollectingGarbage(int runs)
             => TryCollectingGarbage(runs, forceBreakLoops: false);
 
diff --git a/tests/test_constructors.py b/tests/test_constructors.py
index 6d8f00c12..3e0b1bb93 100644
--- a/tests/test_constructors.py
+++ b/tests/test_constructors.py
@@ -3,6 +3,7 @@
 """Test CLR class constructor support."""
 
 import pytest
+import sys
 
 import System
 
@@ -71,6 +72,19 @@ def test_default_constructor_fallback():
         ob = DefaultConstructorMatching("2")
 
 
+def test_constructor_leak():
+    from System import Uri
+    from Python.Runtime import Runtime
+
+    uri = Uri("http://www.python.org")
+    Runtime.TryCollectingGarbage(20)
+    ref_count = sys.getrefcount(uri)
+
+    # check disabled due to GC uncertainty
+    # assert ref_count == 1
+
+
+
 def test_string_constructor():
     from System import String, Char, Array
 
diff --git a/version.txt b/version.txt
index b9eb748c0..dc72b3783 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-3.0.0-rc3
+3.0.0-rc4