diff --git a/autotests/integration/globalshortcuts_test.cpp b/autotests/integration/globalshortcuts_test.cpp
--- a/autotests/integration/globalshortcuts_test.cpp
+++ b/autotests/integration/globalshortcuts_test.cpp
@@ -89,7 +89,6 @@
     kwinApp()->platform()->keyboardKeyPressed(KEY_LEFTSHIFT, timestamp++);
     QCOMPARE(input()->keyboardModifiers(), Qt::ShiftModifier);
     kwinApp()->platform()->keyboardKeyPressed(KEY_5, timestamp++);
-    QEXPECT_FAIL("", "Consumed modifiers are not removed from checking", Continue);
     QTRY_COMPARE(triggeredSpy.count(), 1);
     kwinApp()->platform()->keyboardKeyReleased(KEY_5, timestamp++);
 
diff --git a/autotests/integration/tabbox_test.cpp b/autotests/integration/tabbox_test.cpp
--- a/autotests/integration/tabbox_test.cpp
+++ b/autotests/integration/tabbox_test.cpp
@@ -138,7 +138,6 @@
     QCOMPARE(input()->keyboardModifiers(), Qt::NoModifier);
     QCOMPARE(tabboxClosedSpy.count(), 1);
     QCOMPARE(TabBox::TabBox::self()->isGrabbed(), false);
-    QEXPECT_FAIL("", "capslock modifies the shortcut to walk back", Continue);
     QCOMPARE(workspace()->activeClient(), c2);
 
     surface3.reset();
diff --git a/globalshortcuts.cpp b/globalshortcuts.cpp
--- a/globalshortcuts.cpp
+++ b/globalshortcuts.cpp
@@ -247,16 +247,33 @@
 bool GlobalShortcutsManager::processKey(Qt::KeyboardModifiers mods, uint32_t key)
 {
     if (m_kglobalAccelInterface) {
-        bool retVal = false;
         int keyQt = 0;
         if (KKeyServer::symXToKeyQt(key, &keyQt)) {
-            QMetaObject::invokeMethod(m_kglobalAccelInterface,
-                                    "checkKeyPressed",
-                                    Qt::DirectConnection,
-                                    Q_RETURN_ARG(bool, retVal),
-                                    Q_ARG(int, int(mods) | keyQt));
-            if (retVal) {
+            auto check = [this] (Qt::KeyboardModifiers mods, int keyQt) {
+                bool retVal = false;
+                QMetaObject::invokeMethod(m_kglobalAccelInterface,
+                                         "checkKeyPressed",
+                                         Qt::DirectConnection,
+                                         Q_RETURN_ARG(bool, retVal),
+                                         Q_ARG(int, int(mods) | keyQt));
+                return retVal;
+            };
+            if (check(mods, keyQt)) {
                 return true;
+            } else if (keyQt == Qt::Key_Backtab) {
+                // KGlobalAccel on X11 has some workaround for Backtab
+                // see kglobalaccel/src/runtime/plugins/xcb/kglobalccel_x11.cpp method x11KeyPress
+                // Apparently KKeySequenceWidget captures Shift+Tab instead of Backtab
+                // thus if the key is backtab we should adjust to add shift again and use tab
+                // in addition KWin registers the shortcut incorrectly as Alt+Shift+Backtab
+                // this should be changed to either Alt+Backtab or Alt+Shift+Tab to match KKeySequenceWidget
+                // trying the variants
+                if (check(mods | Qt::ShiftModifier, keyQt)) {
+                    return true;
+                }
+                if (check(mods | Qt::ShiftModifier, Qt::Key_Tab)) {
+                    return true;
+                }
             }
         }
     }
diff --git a/input.cpp b/input.cpp
--- a/input.cpp
+++ b/input.cpp
@@ -436,7 +436,7 @@
     }
     bool keyEvent(QKeyEvent *event) override {
         if (event->type() == QEvent::KeyPress) {
-            return input()->shortcuts()->processKey(event->modifiers(), event->nativeVirtualKey());
+            return input()->shortcuts()->processKey(input()->keyboard()->xkb()->modifiersRelevantForGlobalShortcuts(), event->nativeVirtualKey());
         }
         return false;
     }
diff --git a/keyboard_input.h b/keyboard_input.h
--- a/keyboard_input.h
+++ b/keyboard_input.h
@@ -66,6 +66,7 @@
     QString toString(xkb_keysym_t keysym);
     Qt::Key toQtKey(xkb_keysym_t keysym);
     Qt::KeyboardModifiers modifiers() const;
+    Qt::KeyboardModifiers modifiersRelevantForGlobalShortcuts() const;
     bool shouldKeyRepeat(quint32 key) const;
 
     void switchToNextLayout();
@@ -76,6 +77,7 @@
     void updateKeymap(xkb_keymap *keymap);
     void createKeymapFile();
     void updateModifiers();
+    void updateConsumedModifiers(uint32_t key);
     InputRedirection *m_input;
     xkb_context *m_context;
     xkb_keymap *m_keymap;
@@ -86,6 +88,7 @@
     xkb_mod_index_t m_altModifier;
     xkb_mod_index_t m_metaModifier;
     Qt::KeyboardModifiers m_modifiers;
+    Qt::KeyboardModifiers m_consumedModifiers;
     xkb_keysym_t m_keysym;
     struct {
         uint pressCount = 0;
diff --git a/keyboard_input.cpp b/keyboard_input.cpp
--- a/keyboard_input.cpp
+++ b/keyboard_input.cpp
@@ -91,6 +91,7 @@
     , m_altModifier(0)
     , m_metaModifier(0)
     , m_modifiers(Qt::NoModifier)
+    , m_consumedModifiers(Qt::NoModifier)
     , m_keysym(XKB_KEY_NoSymbol)
 {
     if (!m_context) {
@@ -295,6 +296,7 @@
         }
     }
     updateModifiers();
+    updateConsumedModifiers(key);
     if (state == InputRedirection::KeyboardKeyPressed) {
         m_modOnlyShortcut.pressCount++;
         if (m_modOnlyShortcut.pressCount == 1 &&
@@ -368,6 +370,42 @@
     }
 }
 
+void Xkb::updateConsumedModifiers(uint32_t key)
+{
+    Qt::KeyboardModifiers mods = Qt::NoModifier;
+    if (xkb_state_mod_index_is_consumed(m_state, key + 8, m_shiftModifier) == 1) {
+        mods |= Qt::ShiftModifier;
+    }
+    if (xkb_state_mod_index_is_consumed(m_state, key + 8, m_altModifier) == 1) {
+        mods |= Qt::AltModifier;
+    }
+    if (xkb_state_mod_index_is_consumed(m_state, key + 8, m_controlModifier) == 1) {
+        mods |= Qt::ControlModifier;
+    }
+    if (xkb_state_mod_index_is_consumed(m_state, key + 8, m_metaModifier) == 1) {
+        mods |= Qt::MetaModifier;
+    }
+    m_consumedModifiers = mods;
+}
+
+Qt::KeyboardModifiers Xkb::modifiersRelevantForGlobalShortcuts() const
+{
+    Qt::KeyboardModifiers mods = Qt::NoModifier;
+    if (xkb_state_mod_index_is_active(m_state, m_shiftModifier, XKB_STATE_MODS_EFFECTIVE) == 1) {
+        mods |= Qt::ShiftModifier;
+    }
+    if (xkb_state_mod_index_is_active(m_state, m_altModifier, XKB_STATE_MODS_EFFECTIVE) == 1) {
+        mods |= Qt::AltModifier;
+    }
+    if (xkb_state_mod_index_is_active(m_state, m_controlModifier, XKB_STATE_MODS_EFFECTIVE) == 1) {
+        mods |= Qt::ControlModifier;
+    }
+    if (xkb_state_mod_index_is_active(m_state, m_metaModifier, XKB_STATE_MODS_EFFECTIVE) == 1) {
+        mods |= Qt::MetaModifier;
+    }
+    return mods & ~m_consumedModifiers;
+}
+
 xkb_keysym_t Xkb::toKeysym(uint32_t key)
 {
     if (!m_state) {