diff --git a/Tests/MathLib/TestLinearSolver.cpp b/Tests/MathLib/TestLinearSolver.cpp
index 23f69595d56c0da5f0440b41c43aec9943e687a0..85940cbc316b3d3c8b0efab21ca1eb6e01cb1df9 100644
--- a/Tests/MathLib/TestLinearSolver.cpp
+++ b/Tests/MathLib/TestLinearSolver.cpp
@@ -19,7 +19,6 @@
 #include "MathLib/LinAlg/Dense/DenseMatrix.h"
 #include "MathLib/LinAlg/FinalizeMatrixAssembly.h"
 #include "MathLib/LinAlg/ApplyKnownSolution.h"
-#include "MathLib/LinAlg/Solvers/GaussAlgorithm.h"
 
 #ifdef OGS_USE_EIGEN
 #include "MathLib/LinAlg/Eigen/EigenMatrix.h"
diff --git a/Tests/NumLib/TestSerialLinearSolver.cpp b/Tests/NumLib/TestSerialLinearSolver.cpp
index ab5ab0758f4f332389a3b5474d6410d4054f6ef3..1f3da8cef622f46d428e9ead15e7b9b904d695f9 100644
--- a/Tests/NumLib/TestSerialLinearSolver.cpp
+++ b/Tests/NumLib/TestSerialLinearSolver.cpp
@@ -20,7 +20,6 @@
 #include "MathLib/LinAlg/GlobalMatrixVectorTypes.h"
 #include "MathLib/LinAlg/MatrixSpecifications.h"
 #include "MathLib/LinAlg/MatrixVectorTraits.h"
-#include "MathLib/LinAlg/Solvers/GaussAlgorithm.h"
 #include "MathLib/LinAlg/FinalizeMatrixAssembly.h"
 #include "MathLib/MathTools.h"