diff --git a/maxima.py b/maxima.py
index a3546aa..8095dba 100644
--- a/maxima.py
+++ b/maxima.py
@@ -14,11 +14,36 @@ def find_maxima(x):
     """
 
     idx = []
+    plateau = []
+
     for i in range(len(x)):
+
+        if i != len(x) - 1 and x[i] == x[i+1]:
+            if i not in plateau:
+                plateau.append(i)
+            plateau.append(i+1)
         if i == len(x) - 1:
             if x[i-1] < x[i]:
                 idx.append(i)
+        elif i == 0:
+            if x[i+1] < x[i]:
+                idx.append(i)
         # `i` is a local maximum if the signal decreases before and after it
         elif x[i-1] < x[i] and x[i+1] < x[i]:
             idx.append(i)
+
+    print(plateau)
+    if plateau != []:
+        begin = plateau[0]
+        end = plateau[-1]
+        if end == len(x) - 1:
+            if x[begin-1] < x[begin]:
+                idx = idx + plateau
+        elif begin == 0:
+            if x[end+1] < x[end]:
+                idx = idx + plateau
+        # `i` is a local maximum if the signal decreases before and after it
+        elif x[begin-1] < x[begin] and x[end+1] < x[end]:
+            idx = idx + plateau
+        idx.sort()
     return idx
diff --git a/test_maxima.py b/test_maxima.py
index 7dc59de..28c9428 100644
--- a/test_maxima.py
+++ b/test_maxima.py
@@ -1,42 +1,46 @@
+from maxima import *
 import numpy as np
 
-from maxima import find_maxima
-
-def test_simple_sequence_two_maxima():
-    inp = [0, 1, 2, 1, 2, 1, 0]
-    out = find_maxima(inp)
-    exp = [2, 4]
-    assert exp == out
-
-def test_simple_sequence_one_maximum():
-    inp = [-i**2 for i in range(-3, 4)]
-    out = find_maxima(inp)
-    exp = [3]
-    assert exp == out
-
-def test_sine_wave():
-    inp = [np.sin(2*alpha) for alpha in np.linspace(0.0, 5.0, 100)]
-    out = find_maxima(inp)
-    exp = [16,78]
-    assert exp == out
-
-def test_max_on_both_borders():
-    inp = [4, 2, 1, 3, 1, 2]
-    out = find_maxima(inp)
-    exp = [0,3,5]
-    assert exp == out
-
-# additional tests for
-# - max on both borders
-#   x = [4, 2, 1, 3, 1, 2]
-# - max on both borders, absolute max on right border
-#   x = [4, 2, 1, 3, 1, 5]
-# - one max (absolute) on left border
-#   x = [4, 2, 1, 3, 1]
-# - plateau
-#   x = [1, 2, 2, 1]
-#   (decide for a sensible output in this case)
-# - test cases for plateau
-#   x = [1, 2, 2, 3, 1]
-#   x = [1, 3, 2, 2, 1]
-#   x = [3, 2, 2, 3]
+def test_find_maxima_1():
+    x = [0, 1, 2, 1, 2, 1, 0]
+    assert find_maxima(x) == [2,4]
+
+def test_find_maxima_2():
+    x = [-i**2 for i in range(-3, 4)]
+    assert find_maxima(x) == [3]
+
+def test_find_maxima_3():
+    x = [np.sin(2*alpha) for alpha in np.linspace(0.0, 5.0, 100)]
+    assert find_maxima(x) == [16,78]
+
+def test_find_maxima_4():
+    x = [4, 2, 1, 3, 1, 2]
+    assert find_maxima(x) == [0,3,5]
+
+def test_find_maxima_5():
+    x = [4, 2, 1, 3, 1, 5]
+    assert find_maxima(x) == [0,3,5]
+
+def test_find_maxima_6():
+    x = [4, 2, 1, 3, 1]
+    assert find_maxima(x) == [0,3]
+
+def test_find_maxima_7():
+    x = [1, 2, 2, 1]
+    assert find_maxima(x) == [1,2]
+
+def test_find_maxima_8():
+    x = [1, 2, 2, 3, 1]
+    assert find_maxima(x) == [3]
+
+def test_find_maxima_9():
+    x = [1, 3, 2, 2, 1]
+    assert find_maxima(x) == [1]
+
+def test_find_maxima_10():
+    x = [3, 2, 2, 3]
+    assert find_maxima(x) == [0,3]
+
+def test_find_maxima_11():
+    x = [1, 2, 2, 2, 1]
+    assert find_maxima(x) == [1,2,3]