diff --git a/tests/components/rehlko/test_config_flow.py b/tests/components/rehlko/test_config_flow.py
index 6e3400941ab..661b66e789d 100644
--- a/tests/components/rehlko/test_config_flow.py
+++ b/tests/components/rehlko/test_config_flow.py
@@ -19,7 +19,7 @@ from tests.common import MockConfigEntry
 DHCP_DISCOVERY = DhcpServiceInfo(
     ip="1.1.1.1",
     hostname="KohlerGen",
-    macaddress="00146FAABBCC",
+    macaddress="00146faabbcc",
 )