People with intrinsic sleeve tattoos or wrist tattoos have complained Apple Watch failed to function properly, reported several tech media.

Reddit user guinne55fan posted the new 42 mm SS watch he purchased would automatically lock up when contacting his black inked left arm, even though it was still in full contact with his skin. However, the watch worked perfectly on his tattoo-free hand, according to MacWorld.

Apparently, the Apple Watch malfunctions and is unable to take accurate heart readings since the watch relies on green LEDs to detect blood flow, tattoo ink under the skin would obstruct the light, reported Geek. In addition, it would be difficult for tattoo users to “use Apple Pay through your Watch because it can’t sense you’re alive,” the report added.

Serenity Caldwell noted the design of the tattoo and colors used also had a profound impact on the watch, with darker inks such as black and red causing the most disruption and readings of up to 196 beats per minute (BPM). The average heart rate is 72 BPM, reported Daily Mail.

Lighter colors such as purple and yellow caused slight misreadings of 80 BPM, compared to 69 BPM on a non-tattooed wrist.

The incident has been coined by some on the Internet as Tattoo-gate, and is probably not an issue that Apple can solve through software adjustments. People with wrist or tattoo sleeves probably should wait before getting an Apple Watch.