diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c
index a62b2d3e30..395212a867 100644
--- a/controller/ovn-controller.c
+++ b/controller/ovn-controller.c
@@ -1380,7 +1380,8 @@ static void init_physical_ctx(struct engine_node *node,
 
     struct sbrec_chassis_table *chassis_table =
         (struct sbrec_chassis_table *)EN_OVSDB_GET(
-            engine_get_input("SB_chassis", node));
+            engine_get_input("SB_chassis",
+                engine_get_input("physical_flow_changes", node)));
 
     struct ed_type_mff_ovn_geneve *ed_mff_ovn_geneve =
         engine_get_input_data("mff_ovn_geneve", node);
@@ -1396,7 +1397,8 @@ static void init_physical_ctx(struct engine_node *node,
     const struct sbrec_chassis *chassis = NULL;
     struct ovsdb_idl_index *sbrec_chassis_by_name =
         engine_ovsdb_node_get_index(
-                engine_get_input("SB_chassis", node),
+                engine_get_input("SB_chassis",
+                    engine_get_input("physical_flow_changes", node)),
                 "name");
     if (chassis_id) {
         chassis = chassis_lookup_by_name(sbrec_chassis_by_name, chassis_id);
@@ -1473,7 +1475,8 @@ static void init_lflow_ctx(struct engine_node *node,
     const struct sbrec_chassis *chassis = NULL;
     struct ovsdb_idl_index *sbrec_chassis_by_name =
         engine_ovsdb_node_get_index(
-                engine_get_input("SB_chassis", node),
+            engine_get_input("SB_chassis",
+                engine_get_input("physical_flow_changes", node)),
                 "name");
     if (chassis_id) {
         chassis = chassis_lookup_by_name(sbrec_chassis_by_name, chassis_id);
@@ -1554,8 +1557,9 @@ en_flow_output_run(struct engine_node *node, void *data)
 
     struct ovsdb_idl_index *sbrec_chassis_by_name =
         engine_ovsdb_node_get_index(
-                engine_get_input("SB_chassis", node),
-                "name");
+            engine_get_input("SB_chassis",
+                engine_get_input("physical_flow_changes", node)),
+            "name");
 
     const struct sbrec_chassis *chassis = NULL;
     if (chassis_id) {
@@ -1720,8 +1724,9 @@ _flow_output_resource_ref_handler(struct engine_node *node, void *data,
 
     struct ovsdb_idl_index *sbrec_chassis_by_name =
         engine_ovsdb_node_get_index(
-                engine_get_input("SB_chassis", node),
-                "name");
+            engine_get_input("SB_chassis",
+                engine_get_input("physical_flow_changes", node)),
+            "name");
     const struct sbrec_chassis *chassis = NULL;
     if (chassis_id) {
         chassis = chassis_lookup_by_name(sbrec_chassis_by_name, chassis_id);
@@ -1809,7 +1814,7 @@ flow_output_port_groups_handler(struct engine_node *node, void *data)
 }
 
 struct ed_type_physical_flow_changes {
-    bool ct_zones_changed;
+    bool need_physical_run;
 };
 
 static bool
@@ -1825,8 +1830,8 @@ flow_output_physical_flow_changes_handler(struct engine_node *node, void *data)
     init_physical_ctx(node, rt_data, &p_ctx);
 
     engine_set_node_state(node, EN_UPDATED);
-    if (pfc->ct_zones_changed) {
-        pfc->ct_zones_changed = false;
+    if (pfc->need_physical_run) {
+        pfc->need_physical_run = false;
         physical_run(&p_ctx, &fo->flow_table);
         return true;
     }
@@ -1859,11 +1864,38 @@ physical_flow_changes_ct_zones_handler(struct engine_node *node OVS_UNUSED,
                                       void *data OVS_UNUSED)
 {
     struct ed_type_physical_flow_changes *pfc = data;
-    pfc->ct_zones_changed = true;
+    pfc->need_physical_run = true;
     engine_set_node_state(node, EN_UPDATED);
     return false;
 }
 
+/* Handles sbrec_chassis changes.
+* If a new chassis is added or removed return false, so that
+* physical flows are programmed.
+* For any updates, there is no need for any flow computation.
+* Encap changes will also result in sbrec_chassis changes,
+* but we handle encap changes separately.
+*/
+static bool
+physical_flow_changes_sb_chassis_handler(struct engine_node *node OVS_UNUSED,
+                                         void *data OVS_UNUSED)
+{
+    struct sbrec_chassis_table *chassis_table =
+        (struct sbrec_chassis_table *)EN_OVSDB_GET(
+            engine_get_input("SB_chassis", node));
+    struct ed_type_physical_flow_changes *pfc = data;
+
+    const struct sbrec_chassis *ch;
+    SBREC_CHASSIS_TABLE_FOR_EACH_TRACKED (ch, chassis_table) {
+        if (sbrec_chassis_is_deleted(ch) || sbrec_chassis_is_new(ch)) {
+            pfc->need_physical_run = true;
+            return false;
+        }
+    }
+
+    return true;
+}
+
 static bool
 flow_output_runtime_data_handler(struct engine_node *node,
                                  void *data OVS_UNUSED)
@@ -2072,6 +2104,10 @@ main(int argc, char *argv[])
                      physical_flow_changes_ct_zones_handler);
     engine_add_input(&en_physical_flow_changes, &en_ovs_interface,
                      NULL);
+    engine_add_input(&en_physical_flow_changes, &en_sb_chassis,
+                     physical_flow_changes_sb_chassis_handler);
+    engine_add_input(&en_physical_flow_changes, &en_sb_encap,
+                     NULL);
 
     engine_add_input(&en_flow_output, &en_addr_sets,
                      flow_output_addr_sets_handler);
@@ -2086,8 +2122,6 @@ main(int argc, char *argv[])
     engine_add_input(&en_flow_output, &en_ovs_open_vswitch, NULL);
     engine_add_input(&en_flow_output, &en_ovs_bridge, NULL);
 
-    engine_add_input(&en_flow_output, &en_sb_chassis, NULL);
-    engine_add_input(&en_flow_output, &en_sb_encap, NULL);
     engine_add_input(&en_flow_output, &en_sb_multicast_group,
                      flow_output_sb_multicast_group_handler);
     engine_add_input(&en_flow_output, &en_sb_port_binding,
@@ -2114,7 +2148,8 @@ main(int argc, char *argv[])
                      runtime_data_ovs_interface_handler);
     engine_add_input(&en_runtime_data, &en_ovs_qos, NULL);
 
-    engine_add_input(&en_runtime_data, &en_sb_chassis, NULL);
+    engine_add_input(&en_runtime_data, &en_sb_chassis,
+                     runtime_data_noop_handler);
     engine_add_input(&en_runtime_data, &en_sb_datapath_binding,
                      runtime_data_sb_datapath_binding_handler);
     engine_add_input(&en_runtime_data, &en_sb_port_binding,