diff --git a/src/autotype/x11/AutoTypeX11.cpp b/src/autotype/x11/AutoTypeX11.cpp
index afa0e1de3..c30433095 100644
--- a/src/autotype/x11/AutoTypeX11.cpp
+++ b/src/autotype/x11/AutoTypeX11.cpp
@@ -551,6 +551,9 @@ void AutoTypePlatformX11::ReadKeymap()
     m_altgrMask = 0;
     m_altgrKeysym = NoSymbol;
     modifiers = XGetModifierMapping(m_dpy);
+    /* default value, used if we do not find a mapping */
+    inx_altgr = 3;
+
     for (i = 0; i < 8; i++) {
         for (pos = 0; pos < modifiers->max_keypermod; pos++) {
             keycode = modifiers->modifiermap[i * modifiers->max_keypermod + pos];
@@ -567,12 +570,18 @@ void AutoTypePlatformX11::ReadKeymap()
                     m_altgrMask = 0x0101 << i;
                     /* I don't know why, but 0x2000 was required for mod3 on my Linux box */
                     m_altgrKeysym = keysym;
+
+                    /* set the index of the XGetKeyboardMapping for the AltGr key */
+                    inx_altgr = i;
                 }
             } else if (keysym == XK_ISO_Level3_Shift) {
                 /* if no Mode_switch, try to use ISO_Level3_Shift instead */
                 /* however, it may not work as intended - I don't know why */
                 m_altgrMask = 1 << i;
                 m_altgrKeysym = keysym;
+
+                /* set the index of the XGetKeyboardMapping for the AltGr key */
+                inx_altgr = i;
             }
         }
     }
@@ -631,15 +640,15 @@ void AutoTypePlatformX11::SendKeyPressedEvent(KeySym keysym, unsigned int shift)
                     break;
                 }
             }
-            if (!found && m_altgrMask && 3 <= m_keysymPerKeycode) {
+            if (!found && m_altgrMask && inx_altgr + 1 <= m_keysymPerKeycode) {
                 for (keycode = m_minKeycode; !found && (keycode <= m_maxKeycode); keycode++) {
                     inx = (keycode - m_minKeycode) * m_keysymPerKeycode;
-                    if (m_keysymTable[inx + 2] == keysym) {
+                    if (m_keysymTable[inx + inx_altgr] == keysym) {
                         shift &= ~ShiftMask;
                         shift |= m_altgrMask;
                         found = TRUE;
                         break;
-                    } else if (4 <= m_keysymPerKeycode && m_keysymTable[inx + 3] == keysym) {
+                    } else if (inx_altgr + 2 <= m_keysymPerKeycode && m_keysymTable[inx + inx_altgr + 1] == keysym) {
                         shift |= ShiftMask | m_altgrMask;
                         found = TRUE;
                         break;
diff --git a/src/autotype/x11/AutoTypeX11.h b/src/autotype/x11/AutoTypeX11.h
index 7e67dc83f..0cb88fdaa 100644
--- a/src/autotype/x11/AutoTypeX11.h
+++ b/src/autotype/x11/AutoTypeX11.h
@@ -98,6 +98,8 @@ private:
     int m_altMask;
     int m_metaMask;
     int m_altgrMask;
+    /* index of the XGetKeyboardMapping for the AltGr key */
+    int inx_altgr;
     KeySym m_altgrKeysym;
 };