diff --git a/packages/node_modules/@node-red/nodes/core/function/10-function.js b/packages/node_modules/@node-red/nodes/core/function/10-function.js
index debcb3515..ee54cca50 100644
--- a/packages/node_modules/@node-red/nodes/core/function/10-function.js
+++ b/packages/node_modules/@node-red/nodes/core/function/10-function.js
@@ -479,7 +479,7 @@ module.exports = function(RED) {
     RED.nodes.registerType("function",FunctionNode, {
         dynamicModuleList: "libs",
         settings: {
-            functionExternalModules: { value: true, exportable: true }
+            functionExternalModules: { value: false, exportable: true }
         }
     });
     RED.library.register("functions");
diff --git a/test/nodes/core/function/10-function_spec.js b/test/nodes/core/function/10-function_spec.js
index 7139c0e75..59efd9db4 100644
--- a/test/nodes/core/function/10-function_spec.js
+++ b/test/nodes/core/function/10-function_spec.js
@@ -1416,11 +1416,26 @@ describe('function node', function() {
 
     describe('externalModules', function() {
 
+        it('should fail if using OS module without functionExternalModules set to true', function(done) {
+            var flow = [
+                {id:"n1",type:"function",wires:[["n2"]],func:"msg.payload = os.type(); return msg;", "libs": [{var:"os", module:"os"}]},
+                {id:"n2", type:"helper"}
+            ];
+            helper.load(functionNode, flow, function() {
+                var n1 = helper.getNode("n1");
+                should.not.exist(n1);
+                done();
+            }).catch(err => done(err));
+        })
+
         it('should fail if using OS module without it listed in libs', function(done) {
             var flow = [
                 {id:"n1",type:"function",wires:[["n2"]],func:"msg.payload = os.type(); return msg;"},
                 {id:"n2", type:"helper"}
             ];
+            helper.settings({
+                functionExternalModules: true
+            })
             helper.load(functionNode, flow, function() {
                 var n1 = helper.getNode("n1");
                 var n2 = helper.getNode("n2");
@@ -1444,6 +1459,9 @@ describe('function node', function() {
                 {id:"n1",type:"function",wires:[["n2"]],func:"msg.payload = os.type(); return msg;", "libs": [{var:"os", module:"os"}]},
                 {id:"n2", type:"helper"}
             ];
+            helper.settings({
+                functionExternalModules: true
+            })
             helper.load(functionNode, flow, function() {
                 var n1 = helper.getNode("n1");
                 var n2 = helper.getNode("n2");
@@ -1464,6 +1482,9 @@ describe('function node', function() {
                 {id:"n1",type:"function",wires:[["n2"]],func:"msg.payload = os.type(); return msg;", "libs": [{var:"flow", module:"os"}]},
                 {id:"n2", type:"helper"}
             ];
+            helper.settings({
+                functionExternalModules: true
+            })
             helper.load(functionNode, flow, function() {
                 var n1 = helper.getNode("n1");
                 should.not.exist(n1);