diff --git a/ProcessLib/GroundwaterFlow/Tests.cmake b/ProcessLib/GroundwaterFlow/Tests.cmake
index 13a983ac84126a5fa6a29df75ad98c5cb3189f15..da650d5a542909bec1c1dfe7ab5ab2f0ba8828e2 100644
--- a/ProcessLib/GroundwaterFlow/Tests.cmake
+++ b/ProcessLib/GroundwaterFlow/Tests.cmake
@@ -732,3 +732,26 @@ AddTest(
     python_laplace_eq_ref.vtu square_1e3_neumann_pcs_0_ts_1_t_1.000000.vtu pressure_expected pressure 4e-4 1e-16
 )
 
+AddTest(
+    NAME PythonSourceTermPoissonSinAXSinBYDirichlet_square_1e3
+    PATH Elliptic/square_1x1_GroundWaterFlow_Python
+    EXECUTABLE ogs
+    EXECUTABLE_ARGS square_1e3_poisson_sin_x_sin_y.prj
+    WRAPPER time
+    TESTER vtkdiff
+    REQUIREMENTS OGS_USE_PYTHON AND NOT (OGS_USE_LIS OR OGS_USE_MPI)
+    DIFF_DATA
+    square_1x1_quad_1e3.vtu square_1e3_volumetricsourceterm_pcs_0_ts_1_t_1.000000.vtu analytical_solution pressure 0.7e-2 1e-16
+)
+
+AddTest(
+    NAME PythonSourceTermPoissonSinAXSinBYDirichlet_square_1e5
+    PATH Elliptic/square_1x1_GroundWaterFlow_Python
+    EXECUTABLE ogs
+    EXECUTABLE_ARGS square_1e5_poisson_sin_x_sin_y.prj
+    WRAPPER time
+    TESTER vtkdiff
+    REQUIREMENTS OGS_USE_PYTHON AND NOT (OGS_USE_LIS OR OGS_USE_MPI)
+    DIFF_DATA
+    square_1x1_quad_1e5.vtu square_1e5_volumetricsourceterm_pcs_0_ts_1_t_1.000000.vtu analytical_solution pressure 0.75e-4 1e-16
+)
diff --git a/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e3.vtu b/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e3.vtu
index b56982101f6be9ed1cb17945723023e95d9b9f98..663c9c55ab81712cadb341c8c0ed292e06061245 100644
--- a/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e3.vtu
+++ b/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e3.vtu
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:3653db864dd917e8d5be84d68ee2de13ba3485b1ef23de4e9894fb6749a1aa11
-size 25692
+oid sha256:d3ef47420d7071bfe1a8194048ab0de7b1ab53018814e08235a5c063c95d7609
+size 43824
diff --git a/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e5.vtu b/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e5.vtu
index 2ea9d0e539dcfb5ed6ee2aab13d0cff20bdad1b7..a64c678a9b46fb204c2e9602e4df16d627dec94b 100644
--- a/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e5.vtu
+++ b/Tests/Data/Elliptic/square_1x1_GroundWaterFlow_Python/square_1x1_quad_1e5.vtu
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:ef15af6f3883b743923177105ef59fc8e2695d36f860725e30020b2b088c9d08
-size 2642032
+oid sha256:ff1b3c1c89ed84a64f06112726f5653d0f5c74c2b646f58c8424bc5ba7d0ab99
+size 5678625