This study focused on the question of how to enhance a mastery-goal orientation in the classroom. We started from the perspective of the achievement goal theory, which assumes that the goals that students have (personal goals) relate to the goals that are set in the classroom (classroom goal structures). In classrooms where teachers focus on learning and effort -instead of normative standards and social comparison- mastery goals are enhanced. This type of classroom can be endorsed by focusing on the following classroom structures: "T"ask design, "A"utonomy, "R"ecognition, "G"rouping, "E"valuation, and "T"ime (TARGET). The present study investigated how classroom goal structures as perceived by students are related to students' personal goals. Based on survey data from 501 students from three secondary schools in the Netherlands, we found that the Task design dimension, concerning designing challenging and varied tasks, and the Time dimension, concerning e.g., pacing, predicted both mastery-approach and avoidance goals. Our findings provide insight in how perceived classroom goal structures are related to students' personal goals that focus on understanding/competence, thus informing teachers and educational developers where to start when it comes to improving student motivation.