diff --git a/auth-handler.go b/auth-handler.go
index 3b63824..f26d44e 100644
--- a/auth-handler.go
+++ b/auth-handler.go
@@ -66,6 +66,8 @@ func handleLogout(w http.ResponseWriter, req *http.Request) {
 			tokenInfo := tmp.(Token_Info)
 			log.Printf(blue("User `%s` logged out. Token: %s"), tokenInfo.username, cookie.Value)
 			tokens.Delete(cookie.Value)
+			// Important information, save now
+			go saveTokens()
 		}
 	}
 	// MaxAge: -1 mean deleting cookie
@@ -248,13 +250,14 @@ func buildAuthHandler(handler http.Handler) http.Handler {
 				}
 				// Check useragent and IP address change
 				ip := strings.Split(req.RemoteAddr, ":")[0]
-				lastEntry := tokenInfo.history[len(tokenInfo.history)-1]
-				if (lastEntry.ip != ip) || (lastEntry.useragent != req.UserAgent()) {
-					tokenInfo.history = append(tokenInfo.history, Token_Usage_History{
+				history_key := ip + " " + req.UserAgent()
+				_, history_found := tokenInfo.history[history_key]
+				if !history_found {
+					tokenInfo.history[history_key] = Token_Usage_History{
 						time:      time.Now().Unix(),
 						ip:        ip,
 						useragent: req.UserAgent(),
-					})
+					}
 					tokens.Store(token, tokenInfo)
 					// Important information, save now
 					go saveTokens()
diff --git a/tokens.go b/tokens.go
index 9ed6952..1b60011 100644
--- a/tokens.go
+++ b/tokens.go
@@ -17,11 +17,11 @@ type Token_Info struct {
 	// Updated to the maximum(cfg.MaxNonActiveTime) value on any use of the token
 	countdown int
 	username  string
-	history   []Token_Usage_History
+	history   map[string]Token_Usage_History
 }
 
 type Token_Usage_History struct {
-	time      int64
+	time      int64 // First usage
 	ip        string
 	useragent string
 }
@@ -70,7 +70,8 @@ func newToken(username string, ip string, useragent string) string {
 		ip:        ip,
 		useragent: useragent,
 	}
-	history := []Token_Usage_History{hEntry}
+	history_key := ip + " " + useragent
+	history := map[string]Token_Usage_History{history_key: hEntry}
 	tokenInfo := Token_Info{
 		username:  username,
 		countdown: cfg.MaxNonActiveTime,
@@ -158,7 +159,7 @@ func loadTokens() error {
 			log.Fatal(err)
 		}
 		// Parse token history. Each entry starts with tab
-		history := []Token_Usage_History{}
+		history := map[string]Token_Usage_History{}
 		var hEntry Token_Usage_History
 		for (i+1 < len(lines)) && (len(lines[i+1]) > 0) && (lines[i+1][0] == '\t') {
 			i += 1
@@ -174,7 +175,8 @@ func loadTokens() error {
 			}
 			hEntry.ip = parts[2]
 			hEntry.useragent = parts[3]
-			history = append(history, hEntry)
+			history_key := hEntry.ip + " " + hEntry.useragent
+			history[history_key] = hEntry
 		}
 		// Drop token for deleted user
 		in_tg := false