diff --git a/types/v14.go b/types/v14.go
index 2c354bf..63e6765 100644
--- a/types/v14.go
+++ b/types/v14.go
@@ -54,4 +54,12 @@ type PersistentStateV14 struct {
 		Open       bool  `json:"open"`
 		LastChange int64 `json:"lastchange"`
 	} `json:"state"`
+	Sensors map[string][]PersistentEnvironmentSensor `json:"sensors"`
+}
+
+type PersistentEnvironmentSensor struct {
+	Value      float64 `json:"value"`
+	Location   string  `json:"location"`
+	Name       string  `json:"name"`
+	LastChange int64   `json:"lastchange"`
 }
diff --git a/util/util.go b/util/util.go
index 726d885..282f2e9 100644
--- a/util/util.go
+++ b/util/util.go
@@ -18,8 +18,9 @@ const (
 // the file containing the old state.
 func MergeOldState(response *types.SpaceAPIResponseV14) {
 	var (
-		err      error
-		oldState []byte
+		err            error
+		oldState       []byte
+		persistedState types.PersistentStateV14
 	)
 
 	log.Println("Merging old state from", savedStateJSONPath, "...")
@@ -34,18 +35,35 @@ func MergeOldState(response *types.SpaceAPIResponseV14) {
 		goto removeOld
 	}
 
-	// Read file and merge
+	// Read file and load persisted state
 	oldState, err = os.ReadFile(savedStateJSONPath)
 	if err != nil {
 		log.Println("Error reading old state from", savedStateJSONPath, ", skipping merge... error:", err)
 		goto removeOld
 	}
-	err = json.Unmarshal(oldState, response)
+	err = json.Unmarshal(oldState, &persistedState)
 	if err != nil {
 		log.Println(savedStateJSONPath, "doesn't seem to contain valid data... error:", err)
 		goto removeOld
 	}
 
+	// Merge state
+	response.State = persistedState.State
+
+	// Merge sensors
+	for key, environmentSensors := range persistedState.Sensors {
+		for _, sensor := range environmentSensors {
+			// Order or amount of sensors might have changed, so check sensors already present in response
+			// and then look for matching values in persisted state
+			for i := range response.Sensors[key] {
+				if rs := &response.Sensors[key][i]; rs.Location == sensor.Location && rs.Name == sensor.Name {
+					rs.Value = sensor.Value
+					rs.LastChange = sensor.LastChange
+				}
+			}
+		}
+	}
+
 	// Delete old state json
 removeOld:
 	err = os.RemoveAll(savedStateJSONPath)
@@ -75,6 +93,17 @@ func SaveCurrentState(response types.SpaceAPIResponseV14) {
 			LastChange int64 `json:"lastchange"`
 		}{Open: response.State.Open, LastChange: response.State.LastChange},
 	}
+	// Save sensor state
+	persistentStateV14.Sensors = make(map[string][]types.PersistentEnvironmentSensor)
+	for key, environmentSensors := range response.Sensors {
+		persistentStateV14.Sensors[key] = make([]types.PersistentEnvironmentSensor, len(environmentSensors))
+		for i, sensor := range environmentSensors {
+			persistentStateV14.Sensors[key][i].Value = sensor.Value
+			persistentStateV14.Sensors[key][i].Location = sensor.Location
+			persistentStateV14.Sensors[key][i].Name = sensor.Name
+			persistentStateV14.Sensors[key][i].LastChange = sensor.LastChange
+		}
+	}
 
 	// Serialize persistent state
 	marshal, err := json.MarshalIndent(persistentStateV14, "", "\t")