diff --git a/src/lib/platform/MSWindowsDesks.cpp b/src/lib/platform/MSWindowsDesks.cpp
index 8a4f3b7c..b43a218c 100644
--- a/src/lib/platform/MSWindowsDesks.cpp
+++ b/src/lib/platform/MSWindowsDesks.cpp
@@ -20,7 +20,6 @@
 #include "platform/MSWindowsDesks.h"
 
 #include "platform/MSWindowsScreen.h"
-#include "platform/ImmuneKeysReader.h"
 #include "barrier/IScreenSaver.h"
 #include "barrier/XScreen.h"
 #include "mt/Lock.h"
@@ -89,17 +88,6 @@
 // enable; <unused>
 #define BARRIER_MSG_FAKE_INPUT        BARRIER_HOOK_LAST_MSG + 12
 
-static const std::string ImmuneKeysPath = ArchFileWindows().getProfileDirectory() + "\\ImmuneKeys.txt";
-
-static std::vector<DWORD> immune_keys_list()
-{
-    std::vector<DWORD> keys;
-    std::string badLine;
-    if (!ImmuneKeysReader::get_list(ImmuneKeysPath.c_str(), keys, badLine))
-        LOG((CLOG_ERR "Reading immune keys stopped at: %s", badLine.c_str()));
-    return keys;
-}
-
 //
 // MSWindowsDesks
 //
@@ -126,8 +114,6 @@ MSWindowsDesks::MSWindowsDesks(
     m_events(events),
     m_stopOnDeskSwitch(stopOnDeskSwitch)
 {
-    LOG((CLOG_DEBUG "Immune Keys Path: %s", ImmuneKeysPath.c_str()));
-
     m_cursor    = createBlankCursor();
     m_deskClass = createDeskWindowClass(m_isPrimary);
     m_keyLayout = GetKeyboardLayout(GetCurrentThreadId());
@@ -657,11 +643,6 @@ MSWindowsDesks::deskThread(void* vdesk)
                     MSWindowsHook::uninstallScreenSaver();
                     MSWindowsHook::installScreenSaver();
                 }
-                // populate immune keys list in the DLL's shared memory
-                // before the hooks are activated
-                auto list = immune_keys_list();
-                LOG((CLOG_DEBUG "Found %u immune keys", list.size()));
-                //m_setImmuneKeys(list.data(), list.size());
                 if (!MSWindowsHook::install()) {
                     // we won't work on this desk
                     LOG((CLOG_DEBUG "Cannot hook on this desk"));
diff --git a/src/lib/platform/MSWindowsHook.cpp b/src/lib/platform/MSWindowsHook.cpp
index a27ef981..929888e4 100644
--- a/src/lib/platform/MSWindowsHook.cpp
+++ b/src/lib/platform/MSWindowsHook.cpp
@@ -19,6 +19,7 @@
 
 #include "platform/MSWindowsHook.h"
 #include "platform/MSWindowsHookResource.h"
+#include "platform/ImmuneKeysReader.h"
 #include "barrier/protocol_types.h"
 #include "barrier/XScreen.h"
 #include "base/Log.h"
@@ -49,6 +50,28 @@ static LPARAM            g_deadLParam = 0;
 static BYTE                g_deadKeyState[256] = { 0 };
 static BYTE                g_keyState[256] = { 0 };
 static bool                g_fakeServerInput = false;
+static std::vector<DWORD> g_immuneKeys;
+
+static const std::string ImmuneKeysPath = ArchFileWindows().getProfileDirectory() + "\\ImmuneKeys.txt";
+
+static std::vector<DWORD> immune_keys_list()
+{
+    std::vector<DWORD> keys;
+    std::string badLine;
+    if (!ImmuneKeysReader::get_list(ImmuneKeysPath.c_str(), keys, badLine))
+        LOG((CLOG_ERR "Reading immune keys stopped at: %s", badLine.c_str()));
+    return keys;
+}
+
+inline static
+bool is_immune_key(DWORD target)
+{
+    for (auto key : g_immuneKeys) {
+        if (key == target)
+            return true;
+    }
+    return false;
+}
 
 void
 MSWindowsHook::setSides(UInt32 sides)
@@ -378,9 +401,11 @@ static
 LRESULT CALLBACK
 keyboardLLHook(int code, WPARAM wParam, LPARAM lParam)
 {
-    if (code >= 0) {
-        // decode the message
-        KBDLLHOOKSTRUCT* info = reinterpret_cast<KBDLLHOOKSTRUCT*>(lParam);
+    // decode the message
+    KBDLLHOOKSTRUCT* info = reinterpret_cast<KBDLLHOOKSTRUCT*>(lParam);
+
+    // do not filter non-action events nor immune keys
+    if (code == HC_ACTION && !is_immune_key(info->vkCode)) {
         WPARAM wParam = info->vkCode;
         LPARAM lParam = 1;                            // repeat code
         lParam |= (info->scanCode << 16);        // scan code
@@ -510,7 +535,8 @@ static
 LRESULT CALLBACK
 mouseLLHook(int code, WPARAM wParam, LPARAM lParam)
 {
-    if (code >= 0) {
+    // do not filter non-action events
+    if (code == HC_ACTION) {
         // decode the message
         MSLLHOOKSTRUCT* info = reinterpret_cast<MSLLHOOKSTRUCT*>(lParam);
         SInt32 x = static_cast<SInt32>(info->pt.x);
@@ -536,6 +562,10 @@ MSWindowsHook::install()
     // reset fake input flag
     g_fakeServerInput = false;
 
+    // setup immune keys
+    g_immuneKeys = immune_keys_list();
+    LOG((CLOG_DEBUG "Found %u immune keys in %s", g_immuneKeys.size(), ImmuneKeysPath.c_str()));
+
 #if NO_GRAB_KEYBOARD
     // we only need the mouse hook
     if (!g_hkMouse.set(WH_MOUSE_LL, &mouseLLHook, NULL, 0))