diff --git a/collector/ethtool_linux_test.go b/collector/ethtool_linux_test.go
index 88e91106..761351c6 100644
--- a/collector/ethtool_linux_test.go
+++ b/collector/ethtool_linux_test.go
@@ -270,6 +270,7 @@ func TestBuildEthtoolFQName(t *testing.T) {
 		"Tx LPI entry count":           "node_ethtool_transmitted_lpi_entry_count",
 		"port.VF_admin_queue_requests": "node_ethtool_port_vf_admin_queue_requests",
 		"[3]: tx_bytes":                "node_ethtool_3_transmitted_bytes",
+		"     err":                     "node_ethtool_err",
 	}
 
 	for metric, expected := range testcases {
diff --git a/collector/helper_test.go b/collector/helper_test.go
index e19e5691..15fe5054 100644
--- a/collector/helper_test.go
+++ b/collector/helper_test.go
@@ -70,6 +70,7 @@ func TestSanitizeMetricName(t *testing.T) {
 		"Tx LPI entry count":           "Tx_LPI_entry_count",
 		"port.VF_admin_queue_requests": "port_VF_admin_queue_requests",
 		"[3]: tx_bytes":                "_3_tx_bytes",
+		"     err":                     "_err",
 	}
 
 	for metricName, expected := range testcases {