diff --git a/lib/AdaptiveLighting.js b/lib/AdaptiveLighting.js
index 780e0799..38b6d6ff 100644
--- a/lib/AdaptiveLighting.js
+++ b/lib/AdaptiveLighting.js
@@ -156,6 +156,9 @@ function tlvFromUInt (type, value) {
 
 // Return a TVL buffer for given type and hex string value.
 function tlvFromHexString (type, value) {
+  if (value == null) {
+    return Buffer.alloc(0)
+  }
   return tlvFromBuffer(type, Buffer.from(value, 'hex'))
 }