# How to resolve multiple definition errors when building Calculix with MFront

**URL:** <https://calculix.discourse.group/t/how-to-resolve-multiple-definition-errors-when-building-calculix-with-mfront/3811>\
**Category:** Getting started\
**Created:** [March 5, 2026, 5:50am UTC](https://calculix.discourse.group/t/how-to-resolve-multiple-definition-errors-when-building-calculix-with-mfront/3811 "2026-03-05T05:50:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![k3rrig4n](https://avatars.discourse-cdn.com/v4/letter/k/58f4c7/32.png) [@k3rrig4n](https://calculix.discourse.group/u/k3rrig4n)\
**Post date:** [March 5, 2026, 5:50am UTC](https://calculix.discourse.group/t/how-to-resolve-multiple-definition-errors-when-building-calculix-with-mfront/3811/1 "2026-03-05T05:50:08Z")

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Hello. I am trying to build Calculix with mfront buil library for Barlat plasticity. But i am having an error:  
`/usr/bin/ld: mafillmm.o: in function "mafillmm_": mafillmm.f:(.text+0x0): multiple definition of "mafillmm_"; /tmp/ccV2SgJh.o:mafillmm.f:(.text+0x0): first defined here collect2: error: ld returned 1 exit status make: *** [Makefile_MFront:34: libccx_2.23_helfer.so] Error 1`

I tried to remove this files (all mafill\*.f files) from makefile.inc but it gives another error.  
Any ideas on how to fix that problem?

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<div class="post-metadata">

**Author:** ![k3rrig4n](https://avatars.discourse-cdn.com/v4/letter/k/58f4c7/32.png) [@k3rrig4n](https://calculix.discourse.group/u/k3rrig4n)\
**Post date:** [March 6, 2026, 9:19am UTC](https://calculix.discourse.group/t/how-to-resolve-multiple-definition-errors-when-building-calculix-with-mfront/3811/2 "2026-03-06T09:19:46Z")

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I solved this problem. To compile calculix with mfront (Makefile\_MFront file) you need to delete mafillmm.c line in Makefile.inc file. Then it should be ok.