diff --git a/.coverage b/.coverage
index 5bef51b893ff7f1bc8ea1d4dbecf9ba0018b5b60..dc9fdfb14aa20e5b4806c9472467064144b816c4 100644
Binary files a/.coverage and b/.coverage differ
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index f96626be90aa6698698c9c27fe74b330d53dd691..09fccc7b570a1a4427f31323602303e77c54a493 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,3 +1,9 @@
+v0.3.3.1 (2018-02-10)
+---------------------
+
+* Fixed bug in which MarkovChain.steady_state might use the wrong eigenvector.
+* Added warnings if transition probabilities are negative or don't sum to 1.
+
 v0.3.3.0 (2018-02-08)
 ---------------------
 
diff --git a/dist/prob140-0.3.3.1.tar.gz b/dist/prob140-0.3.3.1.tar.gz
new file mode 100644
index 0000000000000000000000000000000000000000..ecb2d73816ac326c55e916588a38fc41974add44
Binary files /dev/null and b/dist/prob140-0.3.3.1.tar.gz differ
diff --git a/prob140.egg-info/PKG-INFO b/prob140.egg-info/PKG-INFO
index 835ad7a699160f74211b186ec53efca5a7dc8428..8ee928a446b51598892d031b8afed5adfed66510 100644
--- a/prob140.egg-info/PKG-INFO
+++ b/prob140.egg-info/PKG-INFO
@@ -1,12 +1,12 @@
 Metadata-Version: 1.1
 Name: prob140
-Version: 0.3.3.0
+Version: 0.3.3.1
 Summary: A probability library for Berkeley's Prob140 course
 Home-page: http://prob140.org/
 Author: Jason Zhang, Dibya Ghosh
 Author-email: zhang.j@berkeley.edu
 License: GPL
-Download-URL: https://gitlab.com/probability/prob140/raw/master/dist/prob140-0.3.3.0.tar.gz
+Download-URL: https://gitlab.com/probability/prob140/raw/master/dist/prob140-0.3.3.1.tar.gz
 Description-Content-Type: UNKNOWN
 Description: UNKNOWN
 Keywords: data,probability,berkeley,Prob140
diff --git a/prob140/markov_chains.py b/prob140/markov_chains.py
index 9a00526d2414e2ef2d51733044e194c3d1da7891..679d061df489b50716070fa20e3f509633fadcba 100644
--- a/prob140/markov_chains.py
+++ b/prob140/markov_chains.py
@@ -1,4 +1,5 @@
 from collections import OrderedDict
+import warnings
 
 from datascience import Table
 import matplotlib.pyplot as plt
@@ -13,6 +14,11 @@ class MarkovChain:
     """
 
     def __init__(self, states, transition_matrix):
+        transition_matrix = np.array(transition_matrix)
+        if not np.all(transition_matrix >= 0):
+            warnings.warn('Transition matrix contains negative value(s).')
+        if not np.all(np.isclose(np.sum(transition_matrix, axis=1), 1.)):
+            warnings.warn('Transition probabilities don\'t sum to 1.')
         self.states = states
         self.matrix = transition_matrix
 
@@ -287,7 +293,13 @@ class MarkovChain:
         A     | 0.666667
         B     | 0.333333
         """
-        eigenvector = np.real(scipy.linalg.eig(self.matrix, left=True)[1][:, 0])
+        # Steady state is the left eigenvector that corresponds to eigenvalue=1.
+        w, vl = scipy.linalg.eig(self.matrix, left=True, right=False)
+
+        # Find index of eigenvalue = 1.
+        index = np.isclose(w, 1)
+
+        eigenvector = np.real(vl[:, index])[:, 0]
         probabilities = eigenvector / sum(eigenvector)
         return Table().values(self.states).probability(probabilities)
 
diff --git a/prob140/version.py b/prob140/version.py
index 62d12492c18b168a8f807968384ffb68cba1b1c3..03bc7a0e6274b99eaf27ee5fbdf3e11b620adb30 100644
--- a/prob140/version.py
+++ b/prob140/version.py
@@ -1 +1 @@
-__version__ = '0.3.3.0'
+__version__ = '0.3.3.1'
diff --git a/tests/test_markov_chains.py b/tests/test_markov_chains.py
index 41a4420f9cb30600f2898c8dddb9193048f3be75..dfff4d2c40d3cc0813b723b556e9ae13a6844722 100644
--- a/tests/test_markov_chains.py
+++ b/tests/test_markov_chains.py
@@ -78,6 +78,14 @@ def test_construction():
         mc_from_matrix.get_transition_matrix()
     )
 
+    # Negative probability.
+    with pytest.warns(UserWarning):
+        MarkovChain.from_matrix([1, 2], [[-1, 2], [0.5, 0.5]])
+    # Transition probability doesn't sum to 1.
+    with pytest.warns(UserWarning):
+        MarkovChain.from_matrix([1, 2], [[0.2, 0.3], [1, 2]])
+
+
 
 def test_distribution():
     assert_dist_equal(MC_SIMPLE.distribution('A'), [0.1, 0.9])
diff --git a/tests/test_single_variable_plots.ipynb b/tests/test_single_variable_plots.ipynb
index 33c27007823d67c204e74aaa8d56bc05680b3eb2..ede654f87c9e4931ff6d1c0395de266dfbbb674f 100644
--- a/tests/test_single_variable_plots.ipynb
+++ b/tests/test_single_variable_plots.ipynb
@@ -518,7 +518,7 @@
   "language_info": {
    "codemirror_mode": {
     "name": "ipython",
-    "version": 3
+    "version": 3.0
    },
    "file_extension": ".py",
    "mimetype": "text/x-python",
@@ -529,5 +529,5 @@
   }
  },
  "nbformat": 4,
- "nbformat_minor": 1
-}
+ "nbformat_minor": 0
+}
\ No newline at end of file