diff --git a/src/interpolation/interpolation.f90 b/src/interpolation/interpolation.f90
index fbb7167d2..3f61db08b 100644
--- a/src/interpolation/interpolation.f90
+++ b/src/interpolation/interpolation.f90
@@ -98,7 +98,7 @@ SUBROUTINE DefineParametersInterpolation()
 END SUBROUTINE DefineParametersInterpolation
 
 
-SUBROUTINE InitInterpolation(NIn)
+SUBROUTINE InitInterpolation(NIn,NAnalyzeIn)
 !============================================================================================================================
 ! Initialize basis for Gauss-points of order N.
 ! Prepares Differentiation matrices D, D_Hat, Basis at the boundaries L(1), L(-1), L_Hat(1), L_Hat(-1)
@@ -113,7 +113,8 @@ SUBROUTINE InitInterpolation(NIn)
 IMPLICIT NONE
 !----------------------------------------------------------------------------------------------------------------------------
 !input parameters
-INTEGER,INTENT(IN),OPTIONAL :: NIn  !< optional polynomial degree
+INTEGER,INTENT(IN),OPTIONAL :: NIn         !< optional polynomial degree
+INTEGER,INTENT(IN),OPTIONAL :: NAnalyzeIn  !< optional analyze polynomial degree
 !----------------------------------------------------------------------------------------------------------------------------
 !output parameters
 !----------------------------------------------------------------------------------------------------------------------------
@@ -149,8 +150,12 @@ SUBROUTINE InitInterpolation(NIn)
 CALL InitInterpolationBasis(PP_N, xGP, wGP, wBary, L_Minus , L_Plus, L_PlusMinus, swGP=swGP, wGPSurf=wGPSurf)
 
 ! Set the default analyze polynomial degree NAnalyze to 2*(N+1)
-WRITE(DefStr,'(i4)') 2*(PP_N+1)
-NAnalyze = GETINT('NAnalyze',DefStr)
+IF(PRESENT(NAnalyzeIn))THEN
+  NAnalyze = NAnalyzeIn
+ELSE
+  WRITE(DefStr,'(i4)') 2*(PP_N+1)
+  NAnalyze = GETINT('NAnalyze',DefStr)
+END IF ! PRESENT(NAnalyzeIn)
 
 ! Initialize the basis functions for the analyze polynomial
 CALL InitAnalyzeBasis(PP_N,NAnalyze,xGP,wBary)
diff --git a/src/mortar/mortar.f90 b/src/mortar/mortar.f90
index c28cffcfb..bccff63b9 100644
--- a/src/mortar/mortar.f90
+++ b/src/mortar/mortar.f90
@@ -53,7 +53,6 @@ SUBROUTINE InitMortar()
 ! Basic Mortar initialization.
 !===================================================================================================================================
 ! MODULES
-USE MOD_Globals
 USE MOD_Preproc
 USE MOD_Globals
 USE MOD_Interpolation_Vars ,ONLY: InterpolationInitIsDone,NodeType
diff --git a/unitTests/CMakeLists.txt b/unitTests/CMakeLists.txt
index b8a65ad27..364976965 100644
--- a/unitTests/CMakeLists.txt
+++ b/unitTests/CMakeLists.txt
@@ -49,6 +49,7 @@ MESSAGE(STATUS "Executing unit tests with $ENV{CTEST_PARALLEL_LEVEL} processes")
 # Add the unit tests
 add_unit_test(ReadInTools   ./unitTests/ReadInTools.f90)
 add_unit_test(MatrixInverse ./unitTests/MatrixInverse.f90)
+add_unit_test(MortarBasis   ./unitTests/MortarBasis.f90)
 #add_unit_test(NodesAndWeights ./unitTests/NodesAndWeights.f90)
 #add_unit_test(Vandermonde ./unitTests/Vandermonde.f90)
 #add_unit_test(DerivativeMatrix ./unitTests/DerivativeMatrix.f90)
diff --git a/unitTests/MatrixInverse.f90 b/unitTests/MatrixInverse.f90
index 97ab73c7c..6c277a87b 100644
--- a/unitTests/MatrixInverse.f90
+++ b/unitTests/MatrixInverse.f90
@@ -13,10 +13,10 @@
 #include "piclas.h"
 
 !==================================================================================================================================
-!> Unit test 'ReadInToolsUnitTest'
-!> Test the module: MOD_ReadInTools
+!> Unit test 'MatrixInverseUnitTest'
+!> Test the functions: INVERSE_LU, getSPDInverse
 !==================================================================================================================================
-PROGRAM ReadInToolsUnitTest
+PROGRAM MatrixInverseUnitTest
 ! MODULES
 USE MOD_Globals
 USE MOD_ReadInTools
@@ -220,4 +220,4 @@ PROGRAM ReadInToolsUnitTest
 IF(iError.NE.0) CALL abort(__STAMP__,'MPI finalize error')
 #endif
 
-END PROGRAM ReadInToolsUnitTest
+END PROGRAM MatrixInverseUnitTest
diff --git a/unitTests/MortarBasis.f90 b/unitTests/MortarBasis.f90
new file mode 100644
index 000000000..1c7116f66
--- /dev/null
+++ b/unitTests/MortarBasis.f90
@@ -0,0 +1,56 @@
+!==================================================================================================================================
+! Copyright (c) 2023 Stephen M. Copplestone, Patrick Kopper
+!
+! This file is part of PICLas (piclas.boltzplatz.eu/piclas/piclas). PICLas is free software: you can redistribute it and/or modify
+! it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3
+! of the License, or (at your option) any later version.
+!
+! PICLas is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+! of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License v3.0 for more details.
+!
+! You should have received a copy of the GNU General Public License along with PICLas. If not, see <http://www.gnu.org/licenses/>.
+!==================================================================================================================================
+#include "piclas.h"
+
+!==================================================================================================================================
+!> Unit test 'MortarBasisUnitTest'
+!> Test the module: MOD_Mortar, function InitMortar
+!==================================================================================================================================
+PROGRAM MortarBasisUnitTest
+! MODULES
+USE MOD_Globals
+USE MOD_Preproc
+USE MOD_Mortar        ,ONLY: InitMortar,FinalizeMortar
+USE MOD_MPI           ,ONLY: InitMPI
+USE MOD_Interpolation ,ONLY: InitInterpolation,FinalizeInterpolation
+IMPLICIT NONE
+!----------------------------------------------------------------------------------------------------------------------------------
+! LOCAL VARIABLES
+INTEGER           :: nArgs,i
+INTEGER,PARAMETER :: MaxPolDeg=50
+!==================================================================================================================================
+CALL InitMPI()
+! Check for command line arguments to generate the reference solution
+nArgs=COMMAND_ARGUMENT_COUNT()
+IF (nArgs.GT.0) CALL abort(__STAMP__,'ERROR - Unknown command line argument.')
+
+#if PP_N == N
+DO i = 1, MaxPolDeg
+  PP_N = i
+#endif
+  WRITE(*,'(A,I0)') " Testing MortarInit for N = ",PP_N
+  CALL InitInterpolation(PP_N,2*(PP_N+1))
+  CALL InitMortar()
+  CALL FinalizeMortar()
+  CALL FinalizeInterpolation()
+#if PP_N == N
+END DO ! i = 1, MaxPolDeg
+#endif
+
+#if USE_MPI
+! we also have to finalize MPI itself here
+CALL MPI_FINALIZE(iError)
+IF(iError.NE.0) CALL abort(__STAMP__,'MPI finalize error')
+#endif
+
+END PROGRAM MortarBasisUnitTest