diff --git a/src/System.Management.Automation/engine/Utils.cs b/src/System.Management.Automation/engine/Utils.cs
index 70d3ac4a9..7d71e2a13 100644
--- a/src/System.Management.Automation/engine/Utils.cs
+++ b/src/System.Management.Automation/engine/Utils.cs
@@ -200,8 +200,12 @@ namespace System.Management.Automation
             return ecFromTLS.TypeTable;
         }
 
+#if !UNIX
         private static string s_pshome = null;
 
+        /// <summary>
+        /// Get the application base path of the shell from registry
+        /// </summary>
         internal static string GetApplicationBaseFromRegistry(string shellId)
         {
             bool wantPsHome = (object)shellId == (object)DefaultPowerShellShellID;
@@ -226,6 +230,7 @@ namespace System.Management.Automation
 
             return null;
         }
+#endif
 
         /// <summary>
         /// Gets the application base for current monad version
@@ -616,13 +621,18 @@ namespace System.Management.Automation
             return GetRegistryConfigurationPrefix() + "\\" + shellID;
         }
 
-        // Retrieves group policy settings based on the preference order provided:
-        // Dictionary<string, object> settings = GetGroupPolicySetting("Transcription", Registry.LocalMachine, Registry.CurrentUser);
-
+        // Calling static members of 'Registry' on UNIX will raise 'PlatformNotSupportedException' 
+#if UNIX
+        internal static RegistryKey[] RegLocalMachine = null;
+        internal static RegistryKey[] RegCurrentUser = null;
+        internal static RegistryKey[] RegLocalMachineThenCurrentUser = null;
+        internal static RegistryKey[] RegCurrentUserThenLocalMachine = null;
+#else
         internal static RegistryKey[] RegLocalMachine = new[] { Registry.LocalMachine };
         internal static RegistryKey[] RegCurrentUser = new[] { Registry.CurrentUser };
         internal static RegistryKey[] RegLocalMachineThenCurrentUser = new[] { Registry.LocalMachine, Registry.CurrentUser };
         internal static RegistryKey[] RegCurrentUserThenLocalMachine = new[] { Registry.CurrentUser, Registry.LocalMachine };
+#endif
 
         internal static Dictionary<string, object> GetGroupPolicySetting(string settingName, RegistryKey[] preferenceOrder)
         {
diff --git a/src/System.Management.Automation/engine/hostifaces/LocalPipeline.cs b/src/System.Management.Automation/engine/hostifaces/LocalPipeline.cs
index 64719a124..bba09c267 100644
--- a/src/System.Management.Automation/engine/hostifaces/LocalPipeline.cs
+++ b/src/System.Management.Automation/engine/hostifaces/LocalPipeline.cs
@@ -247,6 +247,7 @@ namespace System.Management.Automation.Runspaces
             }
         }
 
+#if !CORECLR
         /// <summary>
         /// Stack Reserve setting for pipeline threads
         /// </summary>
@@ -263,6 +264,38 @@ namespace System.Management.Automation.Runspaces
             }
         }
 
+        internal static int ReadRegistryInt(string policyValueName, int defaultValue)
+        {
+            RegistryKey key;
+            try
+            {
+                key = Registry.LocalMachine.OpenSubKey(Utils.GetRegistryConfigurationPrefix());
+            }
+            catch (System.Security.SecurityException)
+            {
+                return defaultValue;
+            }
+            if (null == key)
+                return defaultValue;
+
+            object temp;
+            try
+            {
+                temp = key.GetValue(policyValueName);
+            }
+            catch (System.Security.SecurityException)
+            {
+                return defaultValue;
+            }
+            if (!(temp is int))
+            {
+                return defaultValue;
+            }
+            int i = (int)temp;
+            return i;
+        }
+#endif
+
         ///<summary>
         /// Helper method for asynchronous invoke
         ///<returns>Unhandled FlowControl exception if InvocationSettings.ExposeFlowControlExceptions is true.</returns>
@@ -531,40 +564,6 @@ namespace System.Management.Automation.Runspaces
             return flowControlException;
         }
 
-        // NTRAID#Windows Out Of Band Releases-915506-2005/09/09
-        // Removed HandleUnexpectedExceptions infrastructure
-
-        internal static int ReadRegistryInt(string policyValueName, int defaultValue)
-        {
-            RegistryKey key;
-            try
-            {
-                key = Registry.LocalMachine.OpenSubKey(Utils.GetRegistryConfigurationPrefix());
-            }
-            catch (System.Security.SecurityException)
-            {
-                return defaultValue;
-            }
-            if (null == key)
-                return defaultValue;
-
-            object temp;
-            try
-            {
-                temp = key.GetValue(policyValueName);
-            }
-            catch (System.Security.SecurityException)
-            {
-                return defaultValue;
-            }
-            if (!(temp is int))
-            {
-                return defaultValue;
-            }
-            int i = (int)temp;
-            return i;
-        }
-
         // NTRAID#Windows Out Of Band Releases-915506-2005/09/09
         // Removed HandleUnexpectedExceptions infrastructure
         /// <summary>