A trio of Senate Democrats are insisting that their vote for a Keystone XL pipeline amendment last week was not an endorsement of the project.

Backers of the oil sands pipeline scored a major win Friday when 17 Democrats joined Republicans in a 62-37 vote in favor of Sen. John Hoeven’s (R-N.D.) amendment.

The amendment’s sponsors said it was a strong show of support for Keystone. But at least three senators who cast surprise “yes” votes — and angered environmentalists — have a different view of the amendment.

Sen. Tom Carper (D-Del.), through an aide, portrayed it as budgetary housekeeping.

“Sen. Carper continues to support letting the approval process by the Department of State and ultimately President Obama go forward,” said Carper spokesman Ian Sams in a statement.