diff --git a/protocols/rdp/include/rdp_keymap.h b/protocols/rdp/include/rdp_keymap.h
index 85eb8f41..0aaa19da 100644
--- a/protocols/rdp/include/rdp_keymap.h
+++ b/protocols/rdp/include/rdp_keymap.h
@@ -118,5 +118,15 @@ extern const guac_rdp_keysym_altcode_map guac_rdp_keysym_altcode;
  */
 extern const int GUAC_KEYSYMS_SHIFT[];
 
+/**
+ * Keysym string containing only the left "alt" key.
+ */
+extern const int GUAC_KEYSYMS_ALT[];
+
+/**
+ * Keysym string containing all modifier keys.
+ */
+extern const int GUAC_KEYSYMS_ALL_MODIFIERS[];
+
 #endif
 
diff --git a/protocols/rdp/src/rdp_keymap.c b/protocols/rdp/src/rdp_keymap.c
index e50c808b..a1a8388d 100644
--- a/protocols/rdp/src/rdp_keymap.c
+++ b/protocols/rdp/src/rdp_keymap.c
@@ -39,3 +39,12 @@
 
 const int GUAC_KEYSYMS_SHIFT[] = {0xFFE1, 0};
 
+const int GUAC_KEYSYMS_ALT[] = {0xFFE9, 0};
+
+const int GUAC_KEYSYMS_ALL_MODIFIERS[] = {
+    0xFFE1, 0xFFE2, /* Left and right shift */
+    0xFFE3, 0xFFE4, /* Left and right control */
+    0xFFE9, 0xFFEA, /* Left and right alt */
+    0
+};
+