diff --git a/tests/test_dynamic_delay_dask.py b/tests/test_dynamic_delay_dask.py
index 0dace5533845365c29911496d89781148a72e84e..466a9e0aa6497510aba232a24300223478424b45 100644
--- a/tests/test_dynamic_delay_dask.py
+++ b/tests/test_dynamic_delay_dask.py
@@ -32,7 +32,7 @@ def test_dynamic_shift_linear_dask() -> None:
     )
     op_np = numpyfy_dask_multi(op_da, chunks=19)
 
-    s_da = op_np(y, d)
+    s_da = op_np(y, -d)
     s_ex = g(np.maximum(t[0], t - d * dt))
 
     assert s_ex == pytest.approx(s_da, abs=1e-15, rel=1e-14)
@@ -63,7 +63,7 @@ def test_dynamic_shift_lagrange_dask() -> None:
     )
     op_na = numpyfy_dask_multi(op_da, chunks=19)
 
-    s_da: np.ndarray = op_na(y, d)
+    s_da: np.ndarray = op_na(y, -d)
     s_ex = g(np.maximum(t[0], t - d * dt))
 
     assert s_ex[op_da.margin_left :] == pytest.approx(
@@ -74,7 +74,7 @@ def test_dynamic_shift_lagrange_dask() -> None:
         length, d.min(), d.max(), DynShiftBC.FLAT, DynShiftBC.EXCEPTION
     )
 
-    s_np = op_np(y, d)
+    s_np = op_np(y, -d)
 
     assert np.all(s_np == s_da)
 
diff --git a/tests/test_dynamic_delay_dsp.py b/tests/test_dynamic_delay_dsp.py
index e1332cc605cea5c6679278f0a53d65ae5f13ac92..08eaec3803f06d402ba2171c93c4d378ca6cd08c 100644
--- a/tests/test_dynamic_delay_dsp.py
+++ b/tests/test_dynamic_delay_dsp.py
@@ -49,7 +49,7 @@ def test_dynamic_shift_dsp_dask() -> None:
     )
     op_na = numpyfy_dask_multi(op_da, chunks=19)
 
-    s_da = op_na(y, d)
+    s_da = op_na(y, -d)
     s_ex = g(np.maximum(t[0], t - d * dt))
 
     assert s_ex[op_da.margin_left :] == pytest.approx(
@@ -60,7 +60,7 @@ def test_dynamic_shift_dsp_dask() -> None:
         order, d.min(), d.max(), DynShiftBC.FLAT, DynShiftBC.EXCEPTION
     )
 
-    s_np = op_np(y, d)
+    s_np = op_np(y, -d)
 
     assert np.all(s_np == s_da)
 
@@ -82,14 +82,14 @@ def test_dynamic_shift_dsp_dask_orders() -> None:
         )
         op1_na = numpyfy_dask_multi(op1_da, chunks=19)
 
-        s1_na = op1_na(y, d)
+        s1_na = op1_na(y, -d)
 
         op2_da = make_dynamic_shift_lagrange_dask(
             length, d.min(), d.max(), DynShiftBC.FLAT, DynShiftBC.EXCEPTION
         )
         op2_na = numpyfy_dask_multi(op2_da, chunks=19)
 
-        s2_na = op2_na(y, d)
+        s2_na = op2_na(y, -d)
 
         assert s1_na == pytest.approx(s2_na, abs=0, rel=5e-15)
 
@@ -120,13 +120,13 @@ def test_fixed_shift_dsp_dask() -> None:
         )
         op2_na = numpyfy_dask_multi(op2_da, chunks=113)
 
-        s1_na = op1_na(y, d)
-        s2_na = op2_na(y, d)
+        s1_na = op1_na(y, -d)
+        s2_na = op2_na(y, -d)
 
         assert s1_na == pytest.approx(s2_na, rel=1e-14, abs=0)
 
         with pytest.raises(RuntimeError):
-            op2_na(y, -d)
+            op2_na(y, d)
 
         op3_da = make_fixed_shift_lagrange_dask(
             DynShiftBC.EXCEPTION, DynShiftBC.FLAT, length
@@ -138,10 +138,10 @@ def test_fixed_shift_dsp_dask() -> None:
         )
         op4_na = numpyfy_dask_multi(op4_da, chunks=113)
 
-        s3_na = op3_na(y, -d)
-        s4_na = op4_na(y, -d)
+        s3_na = op3_na(y, d)
+        s4_na = op4_na(y, d)
 
         assert s3_na == pytest.approx(s4_na, rel=1e-14, abs=0)
 
         with pytest.raises(RuntimeError):
-            op4_na(y, d)
+            op4_na(y, -d)
diff --git a/tests/test_fixed_shift_dask.py b/tests/test_fixed_shift_dask.py
index 3bd8072eefb5640aee2d5946b55974742fc9f246..8ed02ab62da1ee1fbe34e77450e236bb60b980d0 100644
--- a/tests/test_fixed_shift_dask.py
+++ b/tests/test_fixed_shift_dask.py
@@ -48,8 +48,8 @@ def test_fixed_shift_lagrange_dask() -> None:
         )
         op_na = numpyfy_dask_multi(op_da, chunks=113)
 
-        s_np = op_np(y, d)
-        s_na = op_na(y, d)
+        s_np = op_np(y, -d)
+        s_na = op_na(y, -d)
         s_ex = g(t - d * dt)
 
         margin_ex = -int(np.floor(-d)) + order // 2
@@ -58,7 +58,7 @@ def test_fixed_shift_lagrange_dask() -> None:
         assert s_ex[margin_ex:] == pytest.approx(s_na[margin_ex:], abs=1e-15, rel=5e-13)
 
         with pytest.raises(RuntimeError):
-            op_na(y, -d)
+            op_na(y, d)
 
         op2_np = make_fixed_shift_lagrange_numpy(
             DynShiftBC.EXCEPTION, DynShiftBC.FLAT, length
@@ -68,8 +68,8 @@ def test_fixed_shift_lagrange_dask() -> None:
         )
         op2_na = numpyfy_dask_multi(op2_da, chunks=113)
 
-        s2_np = op2_np(y, -d)
-        s2_na = op2_na(y, -d)
+        s2_np = op2_np(y, d)
+        s2_na = op2_na(y, d)
         s2_ex = g(t + d * dt)
 
         margin2_ex = int(np.floor(d)) + (length - 1 - order // 2)
@@ -80,17 +80,17 @@ def test_fixed_shift_lagrange_dask() -> None:
         )
 
         with pytest.raises(RuntimeError):
-            op2_na(y, d)
+            op2_na(y, -d)
 
         op3_da = make_fixed_shift_lagrange_dask(
             DynShiftBC.FLAT, DynShiftBC.FLAT, length
         )
         op3_na = numpyfy_dask_multi(op3_da, chunks=113)
 
-        s3_na = op3_na(y, d)
+        s3_na = op3_na(y, -d)
         assert s3_na == pytest.approx(s_np, rel=1e-14, abs=0)
 
-        s4_na = op3_na(y, -d)
+        s4_na = op3_na(y, d)
         assert s4_na == pytest.approx(s2_np, rel=1e-14, abs=0)
 
 
@@ -119,7 +119,7 @@ def test_shift_lagrange_dask_fixed_vs_dyn() -> None:
             )
             op2_na = numpyfy_dask_multi(op2_da, chunks=113)
 
-            s1_np = op1_na(y, d1d)
-            s2_np = op2_na(y, d)
+            s1_np = op1_na(y, -d1d)
+            s2_np = op2_na(y, -d)
 
             assert s1_np == pytest.approx(s2_np, rel=1e-14, abs=0)
diff --git a/tests/test_fixed_shift_numpy.py b/tests/test_fixed_shift_numpy.py
index bfa90fc9acc154677b4e77e0378f27d9b65ae7dc..c7afb87ec50c1babcc39c8cd188a790947f415f2 100644
--- a/tests/test_fixed_shift_numpy.py
+++ b/tests/test_fixed_shift_numpy.py
@@ -30,7 +30,7 @@ def test_fixed_shift_lagrange_dask() -> None:
             DynShiftBC.FLAT, DynShiftBC.EXCEPTION, length
         )
 
-        s_np = op_np(y, d)
+        s_np = op_np(y, -d)
         s_ex = g(t - d * dt)
 
         margin_ex = -int(np.floor(-d)) + order // 2
@@ -42,13 +42,13 @@ def test_fixed_shift_lagrange_dask() -> None:
         # ~ assert np.min(np.abs(s_ex[:margin_ex] - s_np[:margin_ex])) > np.max(np.abs(y[:margin_ex]))*1e-10
 
         with pytest.raises(RuntimeError):
-            op_np(y, -d)
+            op_np(y, d)
 
         op2_np = make_fixed_shift_lagrange_numpy(
             DynShiftBC.EXCEPTION, DynShiftBC.FLAT, length
         )
 
-        s2_np = op2_np(y, -d)
+        s2_np = op2_np(y, d)
         s2_ex = g(t + d * dt)
 
         margin2_ex = int(np.floor(d)) + (length - 1 - order // 2)
@@ -59,4 +59,4 @@ def test_fixed_shift_lagrange_dask() -> None:
         # ~ assert np.min(np.abs(s2_ex[-margin2_ex:] - s2_np[-margin2_ex:])) > np.max(np.abs(y[-margin2_ex:]))*1e-10
 
         with pytest.raises(RuntimeError):
-            op2_np(y, d)
+            op2_np(y, -d)