diff --git a/src/gui_x11.c b/src/gui_x11.c
index 1402407..f1d9bf8 100644
--- a/src/gui_x11.c
+++ b/src/gui_x11.c
@@ -958,8 +958,7 @@
 
 	// Remove the SHIFT modifier for keys where it's already included,
 	// e.g., '(', '!' and '*'.
-	if (!ASCII_ISALPHA(key) && key > 0x20 && key < 0x7f)
-	    modifiers &= ~MOD_MASK_SHIFT;
+	modifiers = may_remove_shift_modifier(modifiers, key);
     }
 
     if (modifiers != 0)