# Capitalization matters on Windows
**URL:** https://discourse.julialang.org/t/capitalization-matters-on-windows/33345
**Category:** New to Julia
**Created:** [January 14, 2020, 2:02pm UTC](https://discourse.julialang.org/t/capitalization-matters-on-windows/33345 "2020-01-14T14:02:46Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@bocc](https://discourse.julialang.org/u/bocc)
#### Post date: [January 14, 2020, 2:02pm UTC](https://discourse.julialang.org/t/capitalization-matters-on-windows/33345/1 "2020-01-14T14:02:46Z")
I wanted to share an experience of mine, should someone also encounter this.
I am developing my package on Windows, it’s name is an all-capitalized abbreviation in Project.toml, but src/prjname.jl was not capitalized. This caused the following: `]activate .` and `]instantiate` worked just fine, but `using PRJNAME` resulted in a `local package not found` error (even with uuid specification).
Capitalizing the name of the source file solves the issue. (But Git also doesn’t recognize this as a change on Windows…)
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### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [January 14, 2020, 4:41pm UTC](https://discourse.julialang.org/t/capitalization-matters-on-windows/33345/2 "2020-01-14T16:41:31Z")
Similar to Python ([PEP 235](https://www.python.org/dev/peps/pep-0235/)), Julia requires matching case for module import (`using` and `import`) and package operations on case-insensitive case-preserving filesystems (Mac and Windows), for portability and other reasons.
(Simply `open`-ing a file still uses the semantics of the underlying filesystem.)
See also [#5789](https://github.com/JuliaLang/julia/issues/5789), [#17747](https://github.com/JuliaLang/julia/issues/17747), and subsequent PRs.