diff --git a/src/System.Management.Automation/engine/runtime/Operations/ClassOps.cs b/src/System.Management.Automation/engine/runtime/Operations/ClassOps.cs
index 6fb1d9d8ba2..1e451eb8653 100644
--- a/src/System.Management.Automation/engine/runtime/Operations/ClassOps.cs
+++ b/src/System.Management.Automation/engine/runtime/Operations/ClassOps.cs
@@ -43,9 +43,26 @@ internal SessionStateKeeper()
 
         internal void RegisterRunspace()
         {
-            // it's not get, but really 'Add' value.
-            // ConditionalWeakTable.Add throw exception, when you are trying to add a value with the same key.
-            _stateMap.GetValue(Runspace.DefaultRunspace, runspace => runspace.ExecutionContext.EngineSessionState);
+            SessionStateInternal ssInMap = null;
+            Runspace rsToUse = Runspace.DefaultRunspace;
+            SessionStateInternal ssToUse = rsToUse.ExecutionContext.EngineSessionState;
+            
+            // Different threads will operate on different key/value pairs (default-runspace/session-state pairs),
+            // and a ConditionalWeakTable itself is thread safe, so there won't be race condition here.
+            if (!_stateMap.TryGetValue(rsToUse, out ssInMap))
+            {
+                // If the key doesn't exist yet, add it
+                _stateMap.Add(rsToUse, ssToUse);
+            }
+            else if (!ssInMap.Equals(ssToUse))
+            {
+                // If the key exists but the corresponding value is not what we should use, then remove the key/value pair and add the new pair.
+                // This could happen when a powershell class is defined in a module and the module gets reloaded. In such case, the same TypeDefinitionAst
+                // instance will get reused, but should be associated with the SessionState from the new module, instead of the one from the old module.
+                _stateMap.Remove(rsToUse);
+                _stateMap.Add(rsToUse, ssToUse);
+            }
+            // If the key exists and the corresponding value is the one we should use, then do nothing.
         }
 
         /// <summary>
diff --git a/test/powershell/Language/Classes/Scripting.Classes.Modules.Tests.ps1 b/test/powershell/Language/Classes/Scripting.Classes.Modules.Tests.ps1
index 00dfc40246b..3098d2c381b 100644
--- a/test/powershell/Language/Classes/Scripting.Classes.Modules.Tests.ps1
+++ b/test/powershell/Language/Classes/Scripting.Classes.Modules.Tests.ps1
@@ -71,3 +71,43 @@ Import-Module Random
     }
 
 }
+
+Describe 'Module reloading with Class definition' -Tags "CI" {
+
+    BeforeAll {
+        Set-Content -Path TestDrive:\TestModule.psm1 -Value @'
+$passedArgs = $args
+class Root { $passedIn = $passedArgs }
+function Get-PassedArgsRoot { [Root]::new().passedIn }
+function Get-PassedArgsNoRoot { $passedArgs }
+'@
+        $Arg_Hello = 'Hello'
+        $Arg_World = 'World'
+    }
+
+    AfterEach {
+        Remove-Module TestModule -Force -ErrorAction SilentlyContinue
+    }
+
+    It "Class execution reflects changes in module reloading with '-Force'" {
+        Import-Module TestDrive:\TestModule.psm1 -ArgumentList $Arg_Hello
+        Get-PassedArgsRoot | Should Be $Arg_Hello
+        Get-PassedArgsNoRoot | Should Be $Arg_Hello
+
+        Import-Module TestDrive:\TestModule.psm1 -ArgumentList $Arg_World -Force
+        Get-PassedArgsRoot | Should Be $Arg_World
+        Get-PassedArgsNoRoot | Should Be $Arg_World
+    }
+
+    It "Class execution reflects changes in module reloading with 'Remove-Module' and 'Import-Module'" {
+        Import-Module TestDrive:\TestModule.psm1 -ArgumentList $Arg_Hello
+        Get-PassedArgsRoot | Should Be $Arg_Hello
+        Get-PassedArgsNoRoot | Should Be $Arg_Hello
+
+        Remove-Module TestModule
+
+        Import-Module TestDrive:\TestModule.psm1 -ArgumentList $Arg_World
+        Get-PassedArgsRoot | Should Be $Arg_World
+        Get-PassedArgsNoRoot | Should Be $Arg_World
+    }
+}