diff --git a/src/toolbox_scs/base/tests/test_knife_edge.py b/src/toolbox_scs/base/tests/test_knife_edge.py
index 1f06990f780a94c952e557cc99d69b61020a2747..888afbe4e6f0ee063a5531e6e9dc3f3ddf601076 100644
--- a/src/toolbox_scs/base/tests/test_knife_edge.py
+++ b/src/toolbox_scs/base/tests/test_knife_edge.py
@@ -103,7 +103,8 @@ def test_knife_edge_base():
     np.testing.assert_allclose(p0, popt, atol=1e-1)
 
     # Test flipped data
-    popt, _ = knife_edge_base(x, eff_y[::-1])
+    popt, _ = knife_edge_base(x, eff_y[:, ::-1])
+    p0[1] = abs(p0[1])  # Absolute value when flipped
     np.testing.assert_allclose(p0, popt, atol=1e-1)