Xiaomi robot vacuum cleaner does not connect to WI-FI
Solve the problem of connecting the Xiaomi robot vacuum cleaner to Wi-Fi through the Mi Home app. Usually there is an error Bring your phone close to the router. (network connection timeout expired).
If Connected and Message sent to the device is successful, and a red cross appears next to the word Time to connect to the network has elapsed.
- If a particular model of Xiaomi robot vacuum cleaner has been released for the Chinese market (this can be understood from the inscriptions on the box and the device itself, all in Chinese), it is very difficult to add it to the application. The problem is solved by changing the region in the application to China. (try it). But this doesn’t always work. There is information that in this case the phone should be set to Chinese time zone. If all subtitles are in English for European countries (enter one of the European countries in the settings). If all subtitles are in Russian, it means the Russian region.
- Make sure you entered the correct password for the Wi-Fi network you want the vacuum cleaner to connect to when you set up the robotic vacuum cleaner.
- You must have Wi-Fi and Bluetooth enabled on your phone.
- While setting up place the vacuum cleaner and the phone (from which you are setting up) near the router (with the Wi-Fi network to which you will connect the robot vacuum cleaner).
- If it did not work the first time try again. Probably the problem lies on the side of Xiaomi servers.
- Tip from the Комментарии и мнения владельцев: in the app settings turn on all the permissions.
Note! Robots only work on 2.4 GHz frequency. Therefore, it will not be able to connect to Wi-Fi routers operating in a different band.
Changing the region
One of the main reasons for the error is the incompatibility of regions. For example, you bought a Chinese version of the vacuum cleaner, but the Mi Home app is set to the Russian region or vice versa. In this case, you need to change the region to China or mainland China: Settings Language and Region.
It also helps to change the time zone to Chinese try.
Nuances of connection on iOS
Other than the store from which you need to download the Mi Home app, there are no differences in configuration. But there is one problem that occurs only on the iPhone and iPad: the device does not see the vacuum cleaner when you set any region except India and China. To change this, you need to:
- Select India or China.
- Open the Mi Home app;
- Select Profile from the bottom menu, or Profiles in English;
- Select Region;
- Find Settings or Settings;
It is worth trying India first: in this case there will be fewer functional limitations.
Using the modified Mi Home app
The standard Mi Home app from Xiaomi often either does not detect the device, or gives an error about the incompatibility with a particular region. The clever people from thematic forums have long since solved this problem by modifying the program try to connect through it the vacuum cleaner. The author of the modification is user vevs, and you can download the mod here.
- Download your own version of Mi Home. You can find it on the 4PDA site.
- Login to your account in the China region.
- Connect your robot.
- Go to its settings and look for the plugin control. An error message will appear. This is fine.
- Download the plugin without locking the region.
- Go to explorer: internal memory/plugin/install/mpk/615.
- Write down the file name.
- Rename the downloaded plugin so that the names match.
- Copy the new plugin into the 615 folder with a replacement.
If everything was done correctly, the restriction will disappear and the robot will connect to any region. It is suggested to disable automatic update in the app to save installed plugin.
Restore the vacuum cleaner to factory settings
First try just resetting the vacuum cleaner if that does not help, reset it to factory defaults. All of the device data will be restored to its default values.
Adding Wi-Fi devices to MiHome
Most of the smart gadgets in MiHome (with rare exceptions, e.g. wired switches, kettles) powered by 220V have exactly Wi-Fi on board. This is primarily due to the fact that since no batteries (batteries, rechargeable batteries) are used and there is no need to save battery power using more energy efficient protocols Zigbee and Bluetooth, providing maximum speed through faster and cheaper standard Wi-Fi.
To connect Wi-Fi devices, you only need a Wi-Fi router, and there’s no need to purchase additional Zigbee or Bluetooth gateways.
Connecting Wi-Fi gadgets in MiHome
To add a new device to MiHome, click on “” in the right corner of the app. In the appeared context menu you will have 2 options. “Add” and “Scan QR code”.
Choose 1 option. “Add”. If you have enabled the setting in MiHome. “Search for WI-FI devices” (Profile. Settings. Auto Scan. Search for Wi-Fi devices), then when you include a new gadget in the network, its image will appear on top, clicking on which will proceed to add it to our smart home.
If the device is not found, it is possible to select it manually from the list of devices. Before adding a smart gadget to MiHome, you must reset its Wi-Fi settings. For each of these, the wi-fi reset is done by pressing, holding the button/combination of buttons. For information on how to reset the wi-fi settings of your device, you can see it when adding it to MiHome.
For example, let’s add the Smartmi 2 humidifier to MiHome
1 Click on “” in the right corner of the application, then “Add device”. Go to the “Humidifiers” tab and choose our model.
2 Next, using the prompt on the smartphone screen, reset the wi-fi settings of the humidifier, and check that the settings are reset successfully. Next, click on “Connect to another router”, or click on the router if it is detected. Enter the password for our Wi-Fi network so that the humidifier can access the internet.
3 The connection process begins. If everything is fine with the router settings, a “done” button will appear at the end and you can proceed to configure and manage our humidifier. If adding a gadget fails, please follow the steps in order below in this article.
4 MiHome will ask us to select the “Room”. This is a conditional arrangement so that we can quickly move to the desired tab, in this example “Bedroom”. And rename them to your taste, for example Humidifier or Bedroom Humidifier if you have several devices of the same type, so they will be easier to identify. These parameters can be changed at any time as you wish.
5 In the case of this model of humidifier, since it is made for the Chinese market, you will need to additionally replace the plugin or use a subscription to the modified MiHome, so that the plugin is replaced automatically.
IMPORTANT If you suddenly want, for any reason, to move to a different Region of connection of your devices, you will need to reset WI-FI and re-add them to the new server. For example, when migrating from China to Russia using the modified MiHome by Vevs app.
Problems with adding Wi-Fi device
If you for some reason can not add a smart gadget in MiHome, the loading of the plugin fails or there is a message. “Failed to add a device”, do the steps below in order.
1 Make sure the device is in the “right” region. If the box is labeled in Chinese, the power supply has a flat Chinese plug, you need to add it to the region of China. Most of the devices, however, can be added to the region of Russia (or any other) using the MiHome mod (only available on Android).
If the device is added to MiHome when you switch to another region, then the problem was in the region, firmware. If it is still not connected go to step 2
2 Turn on geolocation on your device. Some of them require GPS enabled while connecting.
3 Make sure that the router to which you connect your device has a Wi-Fi network password, Xiaomi smart gadgets will not connect to open Wi-Fi networks.
4 Check if the name of your Wi-Fi network contains any special characters, such as !,@#%^_= и.т.д.
5 Make sure your router is running on 2.4Hz. Sometimes they purposely disable this standard so that everything works on a faster, free channel at 5Hz. But most smart devices are connected exactly to 2.4 Hz
6 If still unable to add the device, try disabling WPA/WPA2-PSK hybrid encryption on the router, leave only WPA2-PSK. In some cases this may solve the problem.
7 If the problem doesn’t go away, give out Wi-Fi with a second smartphone. You can use the access point name and password, as in the home network (router must be unplugged while connected). Try to connect via hotspot. If the connection was successful, then the problem is in the settings of your router/provider. There is a chance that after connecting through the access point of the second smartphone, the gadget will also work on your router, the main problems are exactly at the time of adding to MiHome.
Read the step by step setup on the website:
To connect your Xiaomi vacuum cleaner to your iPhone or Android you will need the Mi Home app. With which you can control the smart vacuum cleaner from your smartphone over a Wi-Fi network. Links for downloading from official resources (opens in a new tab):
We advise downloading via Wi-Fi, files weigh a lot, especially for iPhone and iPad.
Connect your smartphone to Wi-Fi network on frequency 2.4 GHz. Go to the Mi Home app, sign in or register (if this is the first time). Press on the plus sign in upper right corner
Before you connect the robot vacuum cleaner Xiaomi Mi Home app make sure it is charged, t.к. may update when you turn it on for the first time.
Now turn on Bluetooth, and look for the device nearby. If for some reason you could not find the device automatically, you can do it manually. In the Home Appliances tab, select your model. If it is not in the list, then change your region to China.
Next, the application will ask to reset, to do this, press 2 of the 2 buttons or the 2 outermost of the 3, depending on the model, wait for the voice signal in Chinese or English. That’s it, the Wi-Fi settings are reset.
Choose your Wi-Fi network in the next tab, great. Next, the smart vacuum cleaner will synchronize and update. And the rest is set to your liking.
On the main application screen, in the center displays a map of the room, made by the robot vacuum cleaner and its current location. At the top of the screen the name of the vacuum cleaner and the current mode of cleaning.
Information about the distance traveled, cleaning time range, battery level at the bottom of the screen.You can start or stop cleaning there too.
- Go to” button sends the robot to a certain place for unscheduled cleaning.
- The “Dock Station” button sends to the docking station for charging.
- The “Clean” button starts a sequential cleaning.
- The “Zoned Clean” button selects a specific area of the room you want to clean.
There are three dots in the upper right corner to access more settings.
- “Timer” you set the time interval within which you can clean automatically.
- “Voice and volume” change voice packs and volume of voice notifications.
- “Cleaning mode” you choose the intensity of cleaning the room: quiet, turbo, balanced and turbo mode.
- “Cleaning history” recording of cleaning information. Cleaning area, beginning and end of cleaning time.
- “Remote control” manual control, if necessary or have fun.
- “Save Map Mode” adding virtual walls.
- “Carpet mode” specifically for improved carpet cleaning.
- “DND (Do Not Disturb) mode” during the period you choose, the vacuum cleaner will not clean and emit voice notifications.
Now you know how to connect Xiaomi vacuum cleaner and all its functions.
Good to know
- You can control it with Alice voice assistant.
- If you can not connect your Xiaomi vacuum cleaner to Wi-Fi in the document below are tips to solve this problem.
Connecting to Wi-Fi
If the smartphone on Android
Before you connect the robot vacuum cleaner to your mobile device you need to activate its Wi-Fi, GPS and Bluetooth modules, as well as turn on the robot vacuum cleaner Xiaomi. After that, download the proprietary application Mi Home for the Android operating system, which is available on all major software platforms.
Next, the algorithm of connecting the Xiaomi robot vacuum cleaner is as follows:
- In the application you need to register or log in to an existing account by pressing the “Login” button.
- After you successfully launch the application, you need to select the server (region). If available, it is better to choose a server in Europe, Singapore, or the United States. On the Chinese server a number of options may be blocked and unavailable.
- Make sure you have a stable internet signal. The bad quality of the connection may cause the robot vacuum not to function properly as it needs to be “online” in order to do so.
- On the main screen choose the “Add device” line. In the expected list find your device. If the Xiaomi model is not on the list, the robot vacuum cleaner must be entered manually.
- After that, you need to reset the Wi-Fi settings on the robot-vacuum cleaner by simultaneously pressing the two mechanical buttons on the body for 2-3 seconds.
- To complete the process and connect the vacuum cleaner, you need to enter the name of the Wi-Fi network and the password to connect. Next, enter the name of your robot.
- If everything is done correctly, the icon of your Xiaomi model will appear on the main screen of the mobile app.
Thus, via a smartphone using a mobile application, each user will be able to select the mode of Xiaomi, adjust the schedule of cleaning, send the device to the charging station, to control the movement manually and monitor the parameters and wear of the robot vacuum cleaner components.
Features of connecting Xiaomi to iPhone
To connect the robot vacuum cleaner Xiaomi to the iPhone you need to download the application Mi Home from the AppStore. In other respects, the sequence of actions for the iOS operating system is the same as for Android. However, there may be one small problem when trying to connect your smartphone to the Xiaomi robot vacuum cleaner. It lies in the fact that the iPhone is not able to recognize the Xiaomi vacuum cleaner. To fix the situation and connect the device you will need to change the region. To do this, go to the “Profile” section, then to the “Settings” subsection, and click on the “Region” item. Here you need to select India or China.
Can’t connect Xiaomi Mi Roborock Sweep One S50 robotic vacuum cleaner to your home WI-FI
Please help me with the following question. Robot vacuum cleaner Xiaomi Mi Roborock Sweep One S50 International can not connect to the application MiHom. The application is downloaded on the iPad, the home Internet through the router Asus RT-N11P. In the MiHom app, the vacuum cleaner is not automatically visible, manually hooking it is possible, but at the stage of connecting to WI-FI writes “5G WI-FI is not supported”.
In the MiHom app, both Russia and other regions are overridden. Home TVs, tablets and other devices are working with WI-FI for a long time and smoothly. Thanks!
Too bad, of course, that you have not attached screenshots of the application and have not written how you manually hook it and where (at what stage) the error “5G WI-FI is not supported” appears. I don’t have such a vacuum cleaner, and have never set them up.
As far as I understand, the algorithm for connecting and setting up a robot vacuum cleaner is as follows:
- You need to activate the connection mode on the vacuum cleaner. Press and hold down the two buttons, or the power button. To make the light blink. How exactly on the Xiaomi Mi Roborock Sweep One S50. do not know. The manual should show.
- In connection mode, the robot vacuum cleaner gives out WI-FI. Connect to this network from your iPad.
- In the MiHom app, select add a new device.
- The Xiaomi Mi Roborock Sweep One S50 vacuum cleaner should appear there. After that the setting process will start. First of all it will be necessary to choose in the application its WI-FI network (from Asus RT-N11P) and correctly enter the password, so the vacuum cleaner will connect to the router.
- After setup the vacuum cleaner will stop giving out WI-FI, and you will connect your smartphone to your home network. The connection will be through a router.
I don’t understand the “5G WI-FI is not supported” error. I don’t think (although it’s possible) that the Xiaomi Mi Roborock Sweep One S50 only connects to a 5GHz network. Which Asus RT-N11P cannot give out. I do not know what kind of iPad you have. If old, it does not support 5G WI-FI. Maybe that’s the problem.
Judging by the Комментарии и мнения владельцев on this post, the problem with connecting and setting up Xiaomi robotic vacuum cleaners is very popular. I, unfortunately, can not give any specific advice and solutions for the reason that I do not have this device and have no opportunity to check everything myself.
In the Комментарии и мнения владельцев below many visitors to our site shared solutions that helped them to solve the problem with the connection of the robotic vacuum cleaner from Xiaomi to Wi-Fi through the application Mi Home. As a rule, the error “Bring the phone closer to the router” (The network connection timeout has expired) appears.
When the items “Connected” and “Message sent to the device” are successful, and next to “Network connection time has expired” a red cross.
- If exactly your model of robot-vacuum cleaner Xiaomi was released for the Chinese market (this can be understood from the inscriptions on the box and the device itself, there all in Chinese). it is very difficult to add it to the application. The problem seems to be solved by changing the region in the application to “China” (try it). But it does not always work. There is information that in this case, the phone must be set to Chinese time zone. If all captions are in English. for European countries (set one of the European countries in the settings). If all captions are in Russian, it means the region is Russia.
- Make sure that while setting up your robot vacuum cleaner you enter the password for the Wi-Fi network you want the vacuum cleaner to connect to correctly.
- You must have Wi-Fi and Bluetooth enabled on your phone.
- During the setup put the vacuum cleaner and your phone (which you set up) near the router (which Wi-Fi network you will connect the robot vacuum cleaner to).
- If it did not work the first time. Try again. The problem might be on the Xiaomi servers side.
- A tip from the Комментарии и мнения владельцев: turn on all the permissions in the app settings.
- Full reset robot vacuum cleaner.
- The name of your main Wi-Fi network should not contain any special characters and be written in English letters only.
- If you can not set up with an iOS device (iPhone, iPad). then try to configure it from your Android device.
In the Комментарии и мнения владельцев Eugene shared another solution.
There should be no special characters and capital letters in the name of the Wi-Fi network and in the password to this network. Only small letters and numbers. If you can’t connect your Roborock Sweep One S50 to the Wi-Fi network, check the network name (SSID) and password.
Read Комментарии и мнения владельцев. Share your solutions!
Guys, the router did not want to assign an IP to the vacuum cleaner, as evidenced by the network map and its event log. Fixed it by setting static DHCP in the router settings. Hope it helps someone.
It helped to connect to WI-FI 2.4GHz by changing the Wi-Fi protocol to 802.11n Region Russian, language Russian.
Hi, could you please tell me how to change the name of the wi-fi?
Vacuum Cleaner: Roborock S6 MaxV Router: Asus RT-AC66U Phone: Samsung S21 Ultra
Problem: Robot can’t connect to the network (like many people here)
Solution: Here it is very interesting. I originally had no problem with the characters in the network name and password, although I tried those options too. I tried reconfiguring the router itself for different types of networks (ac/n/legacy), changed channels, changed the firewall settings, in general I danced with tambourine on the whole program. I could not connect the vacuum cleaner to the network via the native Roborock app. But by accident I was able to do it through the app Mi Home, and it had nothing to do with the router or the vacuum cleaner (at that time I had already rolled back the router settings to their original state, and reset the Wi-Fi settings on the vacuum cleaner stopped long ago), then I was able to repeat the connection several times. In general, my connection algorithm is as follows: 1) Uninstall the Mi Home app so that the permission to control the Wi-Fi network is lost and install it again 2) Forget the Wi-Fi network of the robot itself 3) Start the standard procedure of connecting the robot to the network, 4) Wait till app gives error that it cannot connect to vacuum cleaner 5) Go to Wi-Fi settings and manually select vacuum cleaner network 6) Go back to app and it should automatically start to connect to vacuum cleaner 7) Almost immediately (within 10 seconds) robot says it starts to connect to network 8) Wait till connection ends
Then everything starts to work. Sometimes it does not work the first time, you need to repeat the algorithm, I, in general, about 5 times successfully connected the vacuum cleaner to the network. With the native app Roborock such Focus does not work.
From all of the above we can draw a simple conclusion, in my case, the problem is neither in the router, nor in the robot, but in the crooked software from Xiaomi. Perhaps with a future update they will fix it.
Hi buddy. I don’t really understand your instructions. Can you explain?( The problem is the same
Cleaner: Roborock S6 MaxV Router: Asus ZenWiFi AX
Worked for a month without problems, then dropped out of WI-FI and everything, now like everyone else on the 3rd stage Bring your phone closer to the router network connection time has expired I have already tried everything in this thread, nothing helped. Network name (all Latin letters with a small letter) Password (only numbers) Encryption methods (WPA WPA3) Regions (Germany, Singapore, China, Ukraine, ) Various installation and reset combinations Mi Home Reset to default settings of the vacuum cleaner, and separately reset WI-FI, 100500 times in each step Reset DHCP on the router, disabled security and firewall, all blocking devices Disabled third-party DNS blocking at the provider Stavil 184.108.40.206 as DNS in the phone and on the router I left only 2.The 4 GHz band on the router, only the n standard, 5 and 6 and automatic channels I tried three different mobile devices with different versions of Android (including Samsung and Xiaomi), one of them with root privileges, and the application itself (Mi Home) gave absolutely all rights
All the settings are rehashed 100 times. Man, well, the router is not an option to change, it’s new, and the money is normal ((( Already my brain starts to melt.
What else to try ? Please help me out
Same thing happened, a couple of weeks went fine, then bam and fell off.
Tried everything on your list too.
I noticed that the vacuum cleaner appears in the router. So it cannot connect to the servers ? (Home Internet Beeline) I gave out the Internet from the phone (MTS) hooked up the vacuum cleaner and everything worked.
I think the Beeline home internet is periodically disconnecting the Xiaomi server. They even have mobile internet and home internet differently opens the sites that on a PC without VPN not plasha, on a mobile internet open normal.
I checked it via mobile internet (MTS) and it works ! Changed provider during this time (now Lanet, Kiev) the same story does not work. I had a feeling it was caused by the router, Asus updated the firmware with security updates and since then it is not working. When changing provider, by the way, I reset the router to factory settings. In the next week I will try to get some other router for testing (not Asus) and I will write here if I get positive results.
The following update came to the router, and everything started to work, I think it was in the 3 item: Firmware version 220.127.116.11.384.81351 1. Fixed guest network related issues. 2. Improved system stability. 3. Fixed android 7 device connection issues.
Tuning before connecting
The first thing to do before connecting to Wi-Fi is to make sure that the robot vacuum cleaner is properly installed. This will not only avoid errors in communication with the smartphone, but also improve the overall performance of the device.
First make sure that there is enough space around the vacuum cleaner station. It should be leaned against the wall. There must be at least 100 cm of free space in front. 50 cm to the left and 50 cm to the right. With this installation, the device will be less likely to get stuck when trying to leave the station or when returning to it.
After connecting the robot to the base, you need to pay attention to the indicator light on the top panel:
- If the light is blinking, installation is correct and the robot is charging;
- The light is on all the time. the battery is full and the cleaner can start working;
- white. enough charge for work, yellow. half, red. critical level is less than 20%, you need to charge the device.
The floor covering should also be prepared, removing large debris, toys, small objects, cables.
Also make sure that the Wi-Fi network has a good signal at the place where the robot is installed. If signal strength is poor the cleaner will not function properly.
At the place of installation it is desirable to have no direct sunlight during the day. Especially in hot regions. The device may overheat and stop working, and in the worst case there is a risk of battery fire.
Setting up the vacuum cleaner without a phone
Unfortunately, in order to connect to Mi Home, it is necessary that the smartphone meets the minimum requirements. Therefore, not all users will be able to control the device remotely. However, all settings can also be done manually:
How to Connect the MI Home App to the MI Robot Vacuum
- Place the charging station on a flat surface near the wall. Within a radius of 1 m from the station, remove unnecessary things so that the device can charge without problems;
- turn on the cable and place the excess part of it in the special hole;
- put the vacuum cleaner on the charging station. If you did everything right, the panel will flash;
- When the cleaner is fully charged, the light will stop blinking.
Now press the power button and the device is ready to work. No additional adjustments need to be made.
Warning! After each cleaning, you need to plug the device into the charging station yourself. At less than 20% charge the light will be red, at 50% it will be yellow, and at full charge the light will turn green.
The app shows that there is something wrong inside the Xiaomi cleaner
Lift the top cover of the Xiaomi robotic vacuum cleaner and hold down the “Reset” hole to reset its system.
If the reset doesn’t work, turn off the unit to check what’s wrong:
- Leave the Xiaomi robotic vacuum cleaner on a flat surface, pull it forward and backward to check the main wheels. If the wheels don’t work, just repair them or replace the wheels with new ones.
- Turn the main brush by hand to check if it works properly. If that doesn’t work, find the cause and fix it or replace a new spinning brush for your Xiaomi vacuum cleaner.
- Connect the vacuum cleaner to Mi Home to update its firmware. If the update doesn’t work, ask your retailer for help.
Xiaomi robot vacuum cleaner doesn’t build a map, or deletes it when it finishes cleaning
Xiaomi has already released several generations of the Mi Robot Vacuum, but here’s the trouble, some people complain that it doesn’t build a map, even though it should, as the manual says.
There are different robot vacuum cleaners, there are common ones like the initial Roomba models, they don’t know how to map the room, but just roll around inside from obstacle to obstacle until they think they have cleaned most of it and then return to the base.
But today there are more and more smart robots that not only build a map of the room they are cleaning in their brains, but also let a person look at it through a special app.
Vacuum cleaners Xiaomi just refer to the second cohort, it’s not just a stupid poloteroki, these robots are fully-fledged, designed to make household chores easier and make life more convenient.
However, on the Internet I meet users’ reviews that Xiaomi robotic vacuum cleaner does not draw a map, or build a map, a person observes the process on the phone screen, but then it completely disappears for some reason.
I personally have not encountered such a problem, but after carefully studying the experience, both in our country and foreign partners, came to the conclusion that there are the following main reasons:
- It is necessary to find out the generation of the vacuum cleaner. The first generation, until recently, did not know how to save the map of the room, it was reset as soon as the cleaning was completed. The second generation is able to map and save, and after the second generation of vacuum cleaners Xiaomi developers have updated the firmware for the first generation, and they can now also build a map and do not forget about it after cleaning. But for this you need to update the firmware to the latest version;
- In some cases, the map is reset if the person himself presses the “Start cleaning” button and does not let the robot return to the base in automatic mode. As I understand it, you need to set a cleaning schedule for the robot and it will not reset the map, it will automatically drive around and clean the area it already knows. If you press the “Clean” button, or give another command that initiates the start of cleaning outside of the schedule, then the card will be automatically deleted from the memory;
- As strange as it sounds, the fact that the card is stored in the robot’s memory is also affected by the region. which is selected in the “Mi Home” app. It is necessary to select the region for sale in which the vacuum cleaner is made. If you bought it officially in. then select “Russia”. If you ordered it with AliExpress and the package does not have a word in English, all spelled out in hieroglyphs, you must choose the region of “China. Or “India”, but then you have to choose by experience.
Above I have described what I was able to learn from other users, if you have something to add, feel free to write Комментарии и мнения владельцев. Perhaps by working together we can create a full-fledged knowledge base, guided by which users will be able to fully use modern smart equipment, the management of which is not always obvious.