An extract from an EU website.An extension on your passport is of no use in the EU. It’s 6 months before the 10 year anniversary of its issue. I’m finding more countries are following this dogma.
If you are a national from a country outside the EU wishing to visit or travel within the EU, you will need a valid passport and possibly a visa. Your passport should be valid for at least 3 months after the date you intend to leave the EU and it must have been issued within the last 10 years. This means your travel document must have been issued within the previous 10 years the day you enter the EU on condition that it is valid until the end of your stay plus an additional 3 months.
Agree with obtaining a new passport to have 6 months before the 10th anniversary. Better safe than sorry.