diff --git a/api/command.py b/api/command.py
index 4c7bc0c..c471cd2 100644
--- a/api/command.py
+++ b/api/command.py
@@ -5,6 +5,7 @@ from .s4_tanks import *
 from .s5_pipes import *
 from .s6_pumps import *
 from .s7_valves import *
+from .s9_demands import *
 
 
 def execute_add_command(name: str, cs: ChangeSet) -> ChangeSet:
@@ -43,6 +44,8 @@ def execute_update_command(name: str, cs: ChangeSet) -> ChangeSet:
         return set_pump(name, cs)
     elif type == VALVE:
         return set_valve(name, cs)
+    elif type == 'demand':
+        return set_demand(name, cs)
 
     return ChangeSet()