diff --git a/src/qibolab/pulses.py b/src/qibolab/pulses.py
index 01f8797e9..a20d7a8b3 100644
--- a/src/qibolab/pulses.py
+++ b/src/qibolab/pulses.py
@@ -218,7 +218,7 @@ def eval(value: str) -> "PulseShape":
         shape_name = re.findall(r"(\w+)", value)[0]
         if shape_name not in globals():
             raise ValueError(f"shape {value} not found")
-        shape_parameters = re.findall(r"[\w+\d\.\d]+", value)[1:]
+        shape_parameters = re.findall(r"[-\w+\d\.\d]+", value)[1:]
         # TODO: create multiple tests to prove regex working correctly
         return globals()[shape_name](*shape_parameters)
 
diff --git a/tests/test_pulses.py b/tests/test_pulses.py
index 8135b3c75..9939b8fae 100644
--- a/tests/test_pulses.py
+++ b/tests/test_pulses.py
@@ -275,12 +275,18 @@ def test_pulses_pulseshape_sampling_rate(shape):
 def test_pulseshape_eval():
     shape = PulseShape.eval("Rectangular()")
     assert isinstance(shape, Rectangular)
-    shape = PulseShape.eval("Drag(5, 1)")
-    assert isinstance(shape, Drag)
     with pytest.raises(ValueError):
         shape = PulseShape.eval("Ciao()")
 
 
+@pytest.mark.parametrize("rel_sigma,beta", [(5, 1), (5, -1), (3, -0.03), (4, 0.02)])
+def test_drag_shape_eval(rel_sigma, beta):
+    shape = PulseShape.eval(f"Drag({rel_sigma}, {beta})")
+    assert isinstance(shape, Drag)
+    assert shape.rel_sigma == rel_sigma
+    assert shape.beta == beta
+
+
 def test_raise_shapeiniterror():
     shape = Rectangular()
     with pytest.raises(ShapeInitError):