Researchers see self-regulated learning (SRL) as a fundamental skill for succeeding in massive open online courses (MOOCs). However, there is no sufficient evidence of adequate functioning of SRL dimensions such as environment structuring, goal setting, time management, help-seeking, task strategies, and self-evaluation in the MOOC environment. This study fills the gap in understanding the structure of SRL skills utilising the Online Self-Regulated Learning Questionnaire (OSLQ). The construct-related validity of the OSLQ is evaluated based on self-reported survey responses of 913 Russian MOOC learners with confirmatory factor analysis and criterion-related validity is checked with independent samples t-tests comparison. The results show that the original six-factor hierarchical model does not fit the data adequately. The evidence implies that the dimension 'help-seeking' is not effective in the MOOC environment. Therefore, a redefined five-factor hierarchical model of the OSLQ is suggested.