Reading is complex task which requires multiple brain areas to communicate efficiently. 17-21% of children struggle to read despite adequate intelligence and instruction. White matter is what allows separate areas of the brain to communicate, and reading difficulties are caused, in part, by differences in these white matter connections. To better understand how white matter matures in children with reading difficulties, we used diffusion magnetic resonance imaging (dMRI) to study dysfluent readers (dysfluent accurate and dysfluent inaccurate) compared to children without reading difficulties. Children received reading assessments and MRI scans twice, 18 months apart. We found that children who were dysfluent readers showed different patterns of white matter maturation than non-impaired readers. In some brain areas, dysfluent readers did not show the expected increases in brain connectivity with age. However, in other areas, they showed faster changes, perhaps suggesting compensation in those areas. This study helps to understand brain changes over time in children with reading difficulties, which is important for appropriate timing of interventions to improve reading ability.