diff --git a/src/app/core/services/keyboard-shortcut.ts b/src/app/core/services/keyboard-shortcut.ts
index b8678f7..9b98b45 100644
--- a/src/app/core/services/keyboard-shortcut.ts
+++ b/src/app/core/services/keyboard-shortcut.ts
@@ -106,8 +106,8 @@
         return;
       }
 
-      if (this.allowedModifiers.indexOf(e.key) > -1) {
-        this.addActiveModifierKey(e.key);
+      if (this.allowedModifiers.indexOf(e.key.toLowerCase()) > -1) {
+        this.addActiveModifierKey(e.key.toLowerCase());
         return;
       }
 
@@ -126,8 +126,8 @@
     });
 
     $('body').on('keyup', (e) => {
-      if (this.allowedModifiers.indexOf(e.key) > -1) {
-        this.removeActiveModifierKey(e.key);
+      if (this.allowedModifiers.indexOf(e.key.toLowerCase()) > -1) {
+        this.removeActiveModifierKey(e.key.toLowerCase());
         return;
       }
     });