Adtran (ADTN) said Wednesday that fiscal Q2 preliminary revenue is now projected to be in the range of $280 million to $282 million, below its prior guidance of $283 million to $303 million.

Analysts polled by FactSet expected $293.4 million.

For fiscal Q3, Adtran expects revenue of $275 million to $295 million and a non-GAAP operating margin of 1.5% to 5.5%. Analysts polled by FactSet expected $300.3 million.

The company said it remains encouraged by demand for its optical networking business despite the near-term headwinds.

The company said it will release its Q2 results Aug. 3.

Adtran shares were down 13% in premarket activity.