Previous research on quality estimation for machine translation has demonstrated the possibility of predicting the translation quality of well-formed data. We present a first study on estimating the translation quality of user-generated con- tent. Our dataset contains English technical forum comments which were trans- lated into French by three automatic systems. These translations were rated in terms of both comprehensibility and fidelity by human annotators. Our experiments show that tried-and-tested quality estimation features work well on this type of data but that extending this set can be beneficial. We also show that the performance of particular types of features de- pends on the type of system used to produce the translation.