diff --git a/tests/test_projection.py b/tests/test_projection.py
index 82f170baf2a894c94447a8591937a68d0acf42b0..371fe0da6bedfa4500f0790be770ba807227976e 100644
--- a/tests/test_projection.py
+++ b/tests/test_projection.py
@@ -44,8 +44,6 @@ def test_genereric_projection():
     projections = pystencils.fields('projections: float32[2D]')
 
     projection_matrix = pystencils_reco.matrix_symbols('T', pystencils.data_types.create_type('float'), 3, 4)
-    from sympy.matrices.dense import MutableDenseMatrix
-    MutableDenseMatrix.__hash__ = lambda x: 1  # hash(tuple(x))
 
     assignments = forward_projection(volume, projections, projection_matrix)
     print(assignments)