diff --git a/gnu/packages/maths.scm b/gnu/packages/maths.scm
index e2f3d84d09b2cbc6bd03e3d51505ed7208886dea..66d60639ab33833b13b877bc9b43fe3d650242b9 100644
--- a/gnu/packages/maths.scm
+++ b/gnu/packages/maths.scm
@@ -3494,7 +3494,11 @@ (define-public dealii-openmpi
         ``("-DMPI_C_COMPILER=mpicc"
            "-DMPI_CXX_COMPILER=mpicxx"
            "-DMPI_Fortran_COMPILER=mpifort"
-           ,@,cf))))
+           ,@,cf))
+       ((#:phases phases '%standard-phases)
+        `(modify-phases ,phases
+           (add-before 'check 'mpi-setup
+             ,%openmpi-setup)))))
     (synopsis "Finite element library (with MPI support)")))
 
 (define-public flann