diff --git a/control/canonical.py b/control/canonical.py
index 5eacce372..bbed5084e 100644
--- a/control/canonical.py
+++ b/control/canonical.py
@@ -64,7 +64,10 @@ def reachable_form(xsys):
             "Canonical forms for MIMO systems not yet supported")
 
     # Create a new system, starting with a copy of the old one
-    zsys = StateSpace(xsys)
+    print(xsys)
+    #print(*xsys)
+    l=[xsys.A,xsys.B,xsys.C,xsys.D,xsys.dt]
+    zsys = StateSpace(*l)
 
     # Generate the system matrices for the desired canonical form
     zsys.B = zeros(shape(xsys.B))
diff --git a/control/setup.py b/control/setup.py
deleted file mode 100644
index 3ed3e3a7e..000000000
--- a/control/setup.py
+++ /dev/null
@@ -1,5 +0,0 @@
-def configuration(parent_package='', top_path=None):
-    from numpy.distutils.misc_util import Configuration
-    config = Configuration('control', parent_package, top_path)
-    config.add_subpackage('tests')
-    return config
diff --git a/control/statesp.py b/control/statesp.py
index 13e662f03..16eca6095 100644
--- a/control/statesp.py
+++ b/control/statesp.py
@@ -91,38 +91,21 @@ class StateSpace(LTI):
 
     """
 
-    def __init__(self, *args):
+    def __init__(self,A,B,C,D,dt=None):
         """Construct a state space object.
 
         The default constructor is StateSpace(A, B, C, D), where A, B, C, D are
         matrices or equivalent objects.  To call the copy constructor, call
         StateSpace(sys), where sys is a StateSpace object.
+        
+        Matrix sizes need to be consistent:
+        A must be square.
+        A and B must have the same number of rows.
+        A and C must have the same number of columns.
+        B and D must have the same number of columns.
+        C and D must have the same number of rows.
 
         """
-
-        if len(args) == 4:
-            # The user provided A, B, C, and D matrices.
-            (A, B, C, D) = args
-            dt = None;
-        elif len(args) == 5:
-            # Discrete time system
-            (A, B, C, D, dt) = args
-        elif len(args) == 1:
-            # Use the copy constructor.
-            if not isinstance(args[0], StateSpace):
-                raise TypeError("The one-argument constructor can only take in \
-a StateSpace object.  Recived %s." % type(args[0]))
-            A = args[0].A
-            B = args[0].B
-            C = args[0].C
-            D = args[0].D
-            try:
-                dt = args[0].dt
-            except NameError:
-                dt = None;
-        else:
-            raise ValueError("Needs 1 or 4 arguments; received %i." % len(args))
-
         A, B, C, D = map(matrix, [A, B, C, D])
 
         # TODO: use super here?
@@ -131,6 +114,7 @@ def __init__(self, *args):
         self.B = B
         self.C = C
         self.D = D
+        self.dt=dt
 
         self.states = A.shape[1]
 
@@ -491,7 +475,7 @@ def minreal(self, tol=0.0):
             except ImportError:
                 raise TypeError("minreal requires slycot tb01pd")
         else:
-            return StateSpace(self)
+            return StateSpace(self.A,self.B,self.C,self.D,self.dt)
 
 
     # TODO: add discrete time check
@@ -545,6 +529,7 @@ def append(self, other):
 
     def __getitem__(self, indices):
         """Array style acces"""
+        
         if len(indices) != 2:
             raise IOError('must provide indices of length 2 for state space')
         i = indices[0]
diff --git a/control/tests/canonical_test.py b/control/tests/canonical_test.py
index f5908a8f4..b980c7591 100644
--- a/control/tests/canonical_test.py
+++ b/control/tests/canonical_test.py
@@ -52,3 +52,10 @@ def test_unreachable_system(self):
 
         # Check if an exception is raised
         np.testing.assert_raises(ValueError, canonical_form, sys, "reachable")
+
+if __name__=="__main__":
+    t=TestCanonical()
+    t.test_reachable_form()
+    t.test_unreachable_system()
+    a=1
+    #unittest.main()
diff --git a/control/tests/discrete_test.py b/control/tests/discrete_test.py
index 2d4f3f457..4be3d6ffb 100644
--- a/control/tests/discrete_test.py
+++ b/control/tests/discrete_test.py
@@ -68,8 +68,12 @@ def testSystemInitialization(self):
 
     def testCopyConstructor(self):
         for sys in (self.siso_ss1, self.siso_ss1c, self.siso_ss1d):
-            newsys = StateSpace(sys);
+            
+            args=[sys.A,sys.B,sys.C,sys.D,sys.dt]
+            newsys = StateSpace(*args);
+            
             self.assertEqual(sys.dt, newsys.dt)
+            
         for sys in (self.siso_tf1, self.siso_tf1c, self.siso_tf1d):
             newsys = TransferFunction(sys);
             self.assertEqual(sys.dt, newsys.dt)