diff --git a/lib/util/settings.js b/lib/util/settings.js
index b2b4074c..a0b3441d 100644
--- a/lib/util/settings.js
+++ b/lib/util/settings.js
@@ -262,6 +262,16 @@ function write() {
 function validate() {
     const validate = ajv.compile(schema);
     const valid = validate(_settings);
+
+    // Verify that all friendly names are unique
+    const names = [];
+    const check = (name) => {
+        if (names.includes(name)) throw new Error(`Duplicate friendly_name '${name}' found`);
+        names.push(name);
+    };
+    Object.values(_settingsWithDefaults.devices).forEach((d) => check(d.friendly_name));
+    Object.values(_settingsWithDefaults.groups).forEach((g) => check(g.friendly_name));
+
     return !valid ? validate.errors.map((v) => `${v.dataPath.substring(1)} ${v.message}`) : null;
 }
 
@@ -444,8 +454,8 @@ function removeDevice(IDorName) {
 }
 
 function addGroup(name) {
-    if (getGroup(name)) {
-        throw new Error(`Group '${name}' already exists`);
+    if (getGroup(name) || getDevice(name)) {
+        throw new Error(`friendly_name '${name}' is already in use`);
     }
 
     const settings = get();
@@ -524,6 +534,10 @@ function changeDeviceOptions(IDorName, newOptions) {
 }
 
 function changeFriendlyName(IDorName, newName) {
+    if (getGroup(newName) || getDevice(newName)) {
+        throw new Error(`friendly_name '${newName}' is already in use`);
+    }
+
     const device = getDeviceThrowIfNotExists(IDorName);
     const settings = get();
     settings.devices[device.ID].friendly_name = newName;
diff --git a/test/settings.test.js b/test/settings.test.js
index aa5e43ec..d18e1fa6 100644
--- a/test/settings.test.js
+++ b/test/settings.test.js
@@ -312,7 +312,7 @@ describe('Settings', () => {
         settings.addGroup('test123');
         expect(() => {
             settings.addGroup('test123');
-        }).toThrow(new Error("Group 'test123' already exists"));
+        }).toThrow(new Error("friendly_name 'test123' is already in use"));
         const expected = {
             '1': {
                 friendly_name: 'test123',
@@ -435,4 +435,32 @@ describe('Settings', () => {
 
         expect(error.message).toContain(`no such file or directory, open`);
     });
+
+    it('Configuration shouldnt be valid when duplicate friendly_name are used', async () => {
+        write(configurationFile, {
+            devices: {'0x0017880104e45519': {friendly_name: 'myname', retain: false}},
+            groups: {'1': {friendly_name: 'myname', retain: false}},
+        });
+
+        settings._reRead();
+
+        expect(() => {
+            settings.validate();
+        }).toThrowError(`Duplicate friendly_name 'myname' found`);
+    });
+
+    it('Configuration shouldnt be valid when duplicate friendly_name are used', async () => {
+        write(configurationFile, {
+            devices: {
+                '0x0017880104e45519': {friendly_name: 'myname', retain: false},
+                '0x0017880104e45511': {friendly_name: 'myname1', retain: false}
+            },
+        });
+
+        settings._reRead();
+
+        expect(() => {
+            settings.changeFriendlyName('myname1', 'myname');
+        }).toThrowError(`friendly_name 'myname' is already in use`);
+    });
 });