diff --git a/pkg/metrics/devices.go b/pkg/metrics/devices.go
index 3bdf351..2b10816 100644
--- a/pkg/metrics/devices.go
+++ b/pkg/metrics/devices.go
@@ -48,6 +48,11 @@ func collectDevices(client *tailscale.Client) []prometheus.Collector {
 			if err != nil {
 				fmt.Println("Failed to get devices: ", err)
 			} else {
+				// Reset gauges so we don't leave old devices around
+				deviceExpiry.Reset()
+				deviceSecondsRemaining.Reset()
+				deviceUpdateAvailable.Reset()
+
 				for _, device := range devices {
 					if !device.KeyExpiryDisabled {
 						remainingSeconds := time.Until(device.Expires.Time).Seconds()
diff --git a/pkg/metrics/keys.go b/pkg/metrics/keys.go
index cd587a5..a0ad8bd 100644
--- a/pkg/metrics/keys.go
+++ b/pkg/metrics/keys.go
@@ -37,6 +37,10 @@ func collectKeys(client *tailscale.Client) []prometheus.Collector {
 			if err != nil {
 				fmt.Println("Failed to get keys: ", err)
 			} else {
+				// Reset gauges so we don't leave old keys around
+				keyExpiry.Reset()
+				keySecondsRemaining.Reset()
+
 				for _, key := range keys {
 					remainingSeconds := time.Until(key.Expires).Seconds()
 					keyType := "auth_key"