diff --git a/red/runtime/nodes/flows/index.js b/red/runtime/nodes/flows/index.js
index a625641b6..2e6d274f0 100644
--- a/red/runtime/nodes/flows/index.js
+++ b/red/runtime/nodes/flows/index.js
@@ -387,9 +387,10 @@ function updateMissingTypes() {
 }
 
 function addFlow(flow) {
-
     var i,node;
-
+    if (!flow.hasOwnProperty('nodes')) {
+        throw new Error('missing nodes property');
+    }
     flow.id = redUtil.generateId();
 
     var nodes = [{
@@ -449,6 +450,9 @@ function getFlow(id) {
     if (flow.label) {
         result.label = flow.label;
     }
+    if (id !== 'global') {
+        result.nodes = [];
+    }
     if (flow.nodes) {
         var nodeIds = Object.keys(flow.nodes);
         if (nodeIds.length > 0) {
@@ -462,6 +466,9 @@ function getFlow(id) {
         result.configs = configIds.map(function(configId) {
             return clone(flow.configs[configId]);
         })
+        if (result.configs.length === 0) {
+            delete result.configs;
+        }
     }
     if (flow.subflows) {
         var subflowIds = Object.keys(flow.subflows);
@@ -480,40 +487,63 @@ function getFlow(id) {
             delete subflow.instances;
             return subflow;
         });
+        if (result.subflows.length === 0) {
+            delete result.subflows;
+        }
     }
     return result;
 }
 
 function updateFlow(id,newFlow) {
-    if (id === 'global') {
-        // TODO: handle global update
-        throw new Error('not allowed to update global');
-    }
-
-    var flow = activeFlowConfig.flows[id];
-    if (!flow) {
-        var e = new Error();
-        e.code = 404;
-        throw e;
+    var label = id;
+    if (id !== 'global') {
+        if (!activeFlowConfig.flows[id]) {
+            var e = new Error();
+            e.code = 404;
+            throw e;
+        }
+        label = activeFlowConfig.flows[id].label;
     }
     var newConfig = clone(activeConfig);
-    newConfig = newConfig.filter(function(node) {
-        return node.z !== id && node.id !== id;
-    });
+    var nodes;
 
-    var tabNode = {
-        type:'tab',
-        label:newFlow.label,
-        id:id
+    if (id === 'global') {
+        // Remove all nodes whose z is not a known flow
+        // When subflows can be owned by a flow, this logic will have to take
+        // that into account
+        newConfig = newConfig.filter(function(node) {
+            return node.type === 'tab' || (node.hasOwnProperty('z') && activeFlowConfig.flows.hasOwnProperty(node.z));
+        })
+
+        // Add in the new config nodes
+        nodes = newFlow.configs||[];
+        if (newFlow.subflows) {
+            // Add in the new subflows
+            newFlow.subflows.forEach(function(sf) {
+                nodes = nodes.concat(sf.nodes||[]).concat(sf.configs||[]);
+                delete sf.nodes;
+                delete sf.configs;
+                nodes.push(sf);
+            });
+        }
+    } else {
+        newConfig = newConfig.filter(function(node) {
+            return node.z !== id && node.id !== id;
+        });
+        var tabNode = {
+            type:'tab',
+            label:newFlow.label,
+            id:id
+        }
+        nodes = [tabNode].concat(newFlow.nodes||[]).concat(newFlow.configs||[]);
+        nodes.forEach(function(n) {
+            n.z = id;
+        });
     }
-    var nodes = [tabNode].concat(newFlow.nodes||[]).concat(newFlow.configs||[]);
-    nodes.forEach(function(n) {
-        n.z = id;
-    });
-    newConfig = newConfig.concat(nodes);
 
+    newConfig = newConfig.concat(nodes);
     return setConfig(newConfig,'flows',true).then(function() {
-        log.info(log._("nodes.flows.updated-flow",{label:(flow.label?flow.label+" ":"")+"["+flow.id+"]"}));
+        log.info(log._("nodes.flows.updated-flow",{label:(label?label+" ":"")+"["+id+"]"}));
     })
 }