diff --git a/src/cthulhu/cthulhu.py b/src/cthulhu/cthulhu.py
index fcf628b..ed26293 100644
--- a/src/cthulhu/cthulhu.py
+++ b/src/cthulhu/cthulhu.py
@@ -72,8 +72,22 @@ class APIHelper:
         # Handle Cthulhu modifier specially
         if "cthulhu+" in key.lower():
             from . import keybindings
-            key = key.lower().replace("cthulhu+", "")
+            key_parts = key.lower().split("+")
             
+            # Determine appropriate modifier mask
+            modifiers = keybindings.CTHULHU_MODIFIER_MASK
+            
+            # Extract the final key (without modifiers)
+            final_key = key_parts[-1]
+            
+            # Check for additional modifiers
+            if "shift" in key_parts:
+                modifiers = keybindings.CTHULHU_SHIFT_MODIFIER_MASK
+            elif "ctrl" in key_parts or "control" in key_parts:
+                modifiers = keybindings.CTHULHU_CTRL_MODIFIER_MASK
+            elif "alt" in key_parts:
+                modifiers = keybindings.CTHULHU_ALT_MODIFIER_MASK
+                
             # Create a keybinding handler
             class GestureHandler:
                 def __init__(self, function, description):
@@ -90,9 +104,9 @@ class APIHelper:
             if cthulhu_state.activeScript:
                 bindings = cthulhu_state.activeScript.getKeyBindings()
                 binding = keybindings.KeyBinding(
-                    key, 
+                    final_key, 
                     keybindings.defaultModifierMask,
-                    keybindings.CTHULHU_MODIFIER_MASK,
+                    modifiers,
                     handler)
                 bindings.add(binding)