diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7e378c4592..7994a58ada 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ For details about compatibility between different releases, see the **Commitment
 
 - Increased the timeout for Basic Station gateways sending HTTP headers. There should now be enough time for embedded devices with little to no hardware acceleration to perform a TLS handshake. In particular, The Things Indoor Gateway can now connect to The Things Stack presenting a ECDSA certificate.
 - Reconnect a gateway when the antenna gain is adjusted.
+- JSON requests where the `eui` field is explicitly set to `null` are no longer converted to an array of zeros.
 
 ### Security
 
diff --git a/pkg/types/types.go b/pkg/types/types.go
index 0e89bea0f9..37ea74ddca 100644
--- a/pkg/types/types.go
+++ b/pkg/types/types.go
@@ -133,8 +133,7 @@ func unmarshalNBytes(s *jsonplugin.UnmarshalState, n int) []byte {
 
 	switch len(trimmed) {
 	case 0:
-		b := make([]byte, n)
-		return b
+		return nil
 	case hex.EncodedLen(n):
 		b, err := hex.DecodeString(trimmed)
 		if err != nil {