When officials asked for the Welsh translation of a road sign, they thought the reply was what they needed.
Unfortunately, the e-mail response to Swansea council said in Welsh: "I am not in the office at the moment. Send any work to be translated".
So that was what went up under the English version which barred lorries from a road near a supermarket.
"When they're proofing signs, they should really use someone who speaks Welsh," said journalist Dylan Iorwerth.
Swansea Council became lost in translation when it was looking to halt heavy goods vehicles using a road near an Asda store in the Morriston area
All official road signs in Wales are bilingual, so the local authority e-mailed its in-house translation service for the Welsh version of: "No entry for heavy goods vehicles. Residential site only".
The reply duly came back and officials set the wheels in motion to create the large sign in both languages.
The notice went up and all seemed well - until Welsh speakers began pointing out the embarrassing error.