Systemic Sclerosis (SSc) is a devastating disease of unknown etiology. Patients suffer from multiple organ fibrosis whereas lung fibrosis (interstitial lung disease, ILD) is one of the main driver for mortality. There is preclinical evidence for efficacy of nintedanib in SSc and associated ILD (SSc-ILD) and the anti-fibrotic efficacy of nintedanib was proven in idiopathic pulmonary fibrosis patients, who are presenting a similar pattern regarding lung fibrosis. Hence it is the purpose of the trial to confirm the efficacy and safety of nintedanib 150 mg bid in treating patients with SSc-ILD, compared with placebo. The trial will be conducted as a double blind, randomised, placebo-controlled trial with primary efficacy evaluation at week 52 and placebo-controlled treatment until last patient out (up to a maximum of 100 weeks). Respiratory function is globally accepted for assessment of treatment effects in patients with lung fibrosis. The chosen endpoint (Forced Vital Capacity (FVC) decline) is easy to obtain and is part of the usual examinations done in patients with SSc-ILD.