diff --git a/control/sysnorm.py b/control/sysnorm.py
index fecdd7095..e1c3b29a0 100644
--- a/control/sysnorm.py
+++ b/control/sysnorm.py
@@ -28,7 +28,7 @@ def _h2norm_slycot(sys, print_warning=True):
     try:
         from slycot import ab13bd
     except ImportError:
-        ct.ControlSlycot("Can't find slycot module ab13bd")
+        raise ct.ControlSlycot("Can't find slycot module ab13bd")
 
     try:
         from slycot.exceptions import SlycotArithmeticError
diff --git a/control/tests/sysnorm_test.py b/control/tests/sysnorm_test.py
index 4b4c6c0e4..1bd04997e 100644
--- a/control/tests/sysnorm_test.py
+++ b/control/tests/sysnorm_test.py
@@ -11,50 +11,54 @@
 import pytest
 
 
-def test_norm_1st_order_stable_system():
+@pytest.mark.parametrize("method", [pytest.param("slycot", marks=pytest.mark.slycot), "scipy", None])
+def test_norm_1st_order_stable_system(method):
     """First-order stable continuous-time system"""
     s = ct.tf('s')
 
     G1 = 1/(s+1)
-    assert np.allclose(ct.norm(G1, p='inf'), 1.0) # Comparison to norm computed in MATLAB
-    assert np.allclose(ct.norm(G1, p=2), 0.707106781186547) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(G1, p='inf', method=method), 1.0) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(G1, p=2, method=method), 0.707106781186547) # Comparison to norm computed in MATLAB
 
     Gd1 = ct.sample_system(G1, 0.1)
-    assert np.allclose(ct.norm(Gd1, p='inf'), 1.0) # Comparison to norm computed in MATLAB
-    assert np.allclose(ct.norm(Gd1, p=2), 0.223513699524858) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(Gd1, p='inf', method=method), 1.0) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(Gd1, p=2, method=method), 0.223513699524858) # Comparison to norm computed in MATLAB
 
 
-def test_norm_1st_order_unstable_system():
+@pytest.mark.parametrize("method", [pytest.param("slycot", marks=pytest.mark.slycot), "scipy", None])
+def test_norm_1st_order_unstable_system(method):
     """First-order unstable continuous-time system"""
     s = ct.tf('s')
 
     G2 = 1/(1-s)
-    assert np.allclose(ct.norm(G2, p='inf'), 1.0) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(G2, p='inf', method=method), 1.0) # Comparison to norm computed in MATLAB
     with pytest.warns(UserWarning, match="System is unstable!"):
-        assert ct.norm(G2, p=2) == float('inf') # Comparison to norm computed in MATLAB
+        assert ct.norm(G2, p=2, method=method) == float('inf') # Comparison to norm computed in MATLAB
 
     Gd2 = ct.sample_system(G2, 0.1)
-    assert np.allclose(ct.norm(Gd2, p='inf'), 1.0) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(Gd2, p='inf', method=method), 1.0) # Comparison to norm computed in MATLAB
     with pytest.warns(UserWarning, match="System is unstable!"):
-        assert ct.norm(Gd2, p=2) == float('inf') # Comparison to norm computed in MATLAB
+        assert ct.norm(Gd2, p=2, method=method) == float('inf') # Comparison to norm computed in MATLAB
 
-def test_norm_2nd_order_system_imag_poles():
+@pytest.mark.parametrize("method", [pytest.param("slycot", marks=pytest.mark.slycot), "scipy", None])
+def test_norm_2nd_order_system_imag_poles(method):
     """Second-order continuous-time system with poles on imaginary axis"""
     s = ct.tf('s')
 
     G3 = 1/(s**2+1)
     with pytest.warns(UserWarning, match="Poles close to, or on, the imaginary axis."):
-        assert ct.norm(G3, p='inf') == float('inf') # Comparison to norm computed in MATLAB
+        assert ct.norm(G3, p='inf', method=method) == float('inf') # Comparison to norm computed in MATLAB
     with pytest.warns(UserWarning, match="Poles close to, or on, the imaginary axis."):
-        assert ct.norm(G3, p=2) == float('inf') # Comparison to norm computed in MATLAB
+        assert ct.norm(G3, p=2, method=method) == float('inf') # Comparison to norm computed in MATLAB
 
     Gd3 = ct.sample_system(G3, 0.1)
     with pytest.warns(UserWarning, match="Poles close to, or on, the complex unit circle."):
-        assert ct.norm(Gd3, p='inf') == float('inf') # Comparison to norm computed in MATLAB
+        assert ct.norm(Gd3, p='inf', method=method) == float('inf') # Comparison to norm computed in MATLAB
     with pytest.warns(UserWarning, match="Poles close to, or on, the complex unit circle."):
-        assert ct.norm(Gd3, p=2) == float('inf') # Comparison to norm computed in MATLAB
+        assert ct.norm(Gd3, p=2, method=method) == float('inf') # Comparison to norm computed in MATLAB
 
-def test_norm_3rd_order_mimo_system():
+@pytest.mark.parametrize("method", [pytest.param("slycot", marks=pytest.mark.slycot), "scipy", None])
+def test_norm_3rd_order_mimo_system(method):
     """Third-order stable MIMO continuous-time system"""
     A = np.array([[-1.017041847539126,  -0.224182952826418,   0.042538079149249],
                   [-0.310374015319095,  -0.516461581407780,  -0.119195790221750],
@@ -66,9 +70,29 @@ def test_norm_3rd_order_mimo_system():
                   [-0.863652821988714,  -1.214117043615409,  -0.006849328103348]])
     D = np.zeros((2,2))
     G4 = ct.ss(A,B,C,D) # Random system generated in MATLAB
-    assert np.allclose(ct.norm(G4, p='inf'), 4.276759162964244) # Comparison to norm computed in MATLAB
-    assert np.allclose(ct.norm(G4, p=2), 2.237461821810309) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(G4, p='inf', method=method), 4.276759162964244) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(G4, p=2, method=method), 2.237461821810309) # Comparison to norm computed in MATLAB
 
     Gd4 = ct.sample_system(G4, 0.1)
-    assert np.allclose(ct.norm(Gd4, p='inf'), 4.276759162964228) # Comparison to norm computed in MATLAB
-    assert np.allclose(ct.norm(Gd4, p=2), 0.707434962289554) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(Gd4, p='inf', method=method), 4.276759162964228) # Comparison to norm computed in MATLAB
+    assert np.allclose(ct.norm(Gd4, p=2, method=method), 0.707434962289554) # Comparison to norm computed in MATLAB
+
+
+@pytest.mark.noslycot
+def test_sysnorm_no_slycot():
+    """Test that sysnorm raises ControlSlycot when slycot is requested but not available"""
+    s = ct.tf('s')
+    G = 1/(s+1)
+
+    with pytest.raises(ct.ControlSlycot, match="Can't find slycot module ab13bd"):
+        ct.norm(G, p=2, method='slycot')
+
+
+def test_norm_invalid_p():
+    """Test that norm raises Error for invalid norm request"""
+    s = ct.tf('s')
+    G = 1/(s+1)
+
+    with pytest.raises(ct.ControlArgument,
+                       match="Norm computation for p=myownnorm currently not supported."):
+        ct.norm(G, p='myownnorm', method=None)