# Could not load library "libmpfr"

**URL:** <https://discourse.julialang.org/t/could-not-load-library-libmpfr/140131>\
**Category:** General Usage\
**Tags:** question\
**Created:** [October 21, 2026, 8:02am UTC](https://discourse.julialang.org/t/could-not-load-library-libmpfr/140131 "2026-10-21T08:02:05Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![TimG](https://avatars.discourse-cdn.com/v4/letter/t/82dd89/32.png) [@TimG](https://discourse.julialang.org/u/TimG)\
**Post date:** [October 21, 2026, 8:02am UTC](https://discourse.julialang.org/t/could-not-load-library-libmpfr/140131/1 "2026-10-21T08:02:05Z")

</div>

I’m confused by this issue: [Windows: packages that `ccall` `:libmpfr` by bare name fail since #63686 · Issue #63849 · JuliaLang/julia](https://github.com/JuliaLang/julia/issues/63849) which is declared closed.

CI on XLSX.jl now fails on both Julia nightly and Julia pre, and the message is:

```julia-auto
ERROR: LoadError: could not load library "libmpfr"
  The specified module could not be found. 
  in expression starting at C:\Users\runneradmin\.julia\packages\IrrationalConstants\RokwY\src\stats.jl:26
  in expression starting at C:\Users\runneradmin\.julia\packages\IrrationalConstants\RokwY\src\IrrationalConstants.jl:1
  in expression starting at stdin:5
                ✗ IrrationalConstants

```

My declared compats are:

```julia-auto
[compat]
Colors = "0.12, 0.13"
Dates = "1.10"
FileIO = "1"
OrderedCollections = "1, 2.0"
Parsers = "2.8, 3"
PrecompileTools = "1"
Printf = "1.10"
Random = "1.10"
StyledStrings = "1.0.3"
Tables = "1"
UUIDs = "1.8"
Unicode = "1.10"
XML = "0.4.6"
ZipArchives = "2.5"
julia = "1.10"

```

and in tests:

```julia-auto
[compat]
Aqua = "0.8"
Colors = "0.12, 0.13"
CSV = "0.10.15, 1"
Distributions = "0.25.0"
FileIO = "1"
OrderedCollections = "1, 2"
Pkg = "1"
StyledStrings = "1.0.3"
Tables = "1"
XML = "0.4.6"
ZipArchives = "2.5"
julia = "1.10"

```

Is this a temporary issue that will fix itself or is there something I must do myself to fix this? Do my compats need updating (Dependabot is silent so far)?