diff --git a/kitty/client.py b/kitty/client.py
index c119cb3ad..11ba4a46e 100644
--- a/kitty/client.py
+++ b/kitty/client.py
@@ -75,7 +75,7 @@ def screen_set_margins(t, b):
 
 
 def screen_indexn(n):
-    write(CSI + '%dS')
+    write(CSI + '%dS' % n)
 
 
 def screen_erase_in_display(how, private):
diff --git a/kitty_tests/parser.py b/kitty_tests/parser.py
index 74c111377..a627f8eee 100644
--- a/kitty_tests/parser.py
+++ b/kitty_tests/parser.py
@@ -173,7 +173,7 @@ class TestParser(BaseTest):
         c.clear()
         pb('\033]2;;;;\x07', ('set_title', ';;;'))
         self.ae(c.titlebuf, ';;;')
-        pb('\033]110\x07', ('set_dynamic_color', ''))
+        pb('\033]110\x07', ('set_dynamic_color', 110, ''))
         self.ae(c.colorbuf, '')
 
     def test_dcs_codes(self):