diff --git a/bridge.go b/bridge.go
index fd54d85..31cc589 100644
--- a/bridge.go
+++ b/bridge.go
@@ -393,7 +393,7 @@ func (br *Bridge) AddDevicesFromJSON(devJson []byte) error {
 
 		acc, exp, err := createAccessory(&dev)
 		if err != nil {
-			if err == ErrDeviceSkipped {
+			if err == ErrDeviceSkipped || err == ErrUnknownDeviceType {
 				continue
 			}
 			return err
diff --git a/z2m.go b/z2m.go
index 7aeaa86..b16f24c 100644
--- a/z2m.go
+++ b/z2m.go
@@ -23,8 +23,9 @@ var IgnoreProperties = map[string]bool{
 }
 
 var (
-	ErrDeviceSkipped  = fmt.Errorf("device is skipped")
-	ErrMalfomedDevice = fmt.Errorf("device is malformed")
+	ErrDeviceSkipped     = fmt.Errorf("device is skipped")
+	ErrMalfomedDevice    = fmt.Errorf("device is malformed")
+	ErrUnknownDeviceType = fmt.Errorf("device type is unknown")
 
 	ErrNotNumericCharacteristic = fmt.Errorf("characteristic is non-numeric")
 )
@@ -119,6 +120,11 @@ func createAccessory(dev *Device) (*accessory.A, []*ExposeMapping, error) {
 		allExposes = append(allExposes, exposes...)
 	}
 
+	// if no Exposes entry was processed, return error
+	if len(allExposes) == 0 {
+		return nil, nil, ErrUnknownDeviceType
+	}
+
 	// copy value ranges
 	for _, e := range allExposes {
 		if e.ExposesEntry.Type != "numeric" {
@@ -316,6 +322,7 @@ func (m *ExposeMapping) ToExposedValue(v any) (any, error) {
 			expVal = m.ExposesEntry.ValueOn
 		}
 	}
+
 	return expVal, err
 }