diff --git a/maxima.py b/maxima.py
index ed03ef6..6a3e500 100644
--- a/maxima.py
+++ b/maxima.py
@@ -1,3 +1,5 @@
+import numpy as np
+
 def find_maxima(x):
     """Find local maxima of x.
 
@@ -14,8 +16,26 @@ def find_maxima(x):
     """
 
     idx = []
+    bfr = []
+    up = True
     for i in range(len(x)):
         # `i` is a local maximum if the signal decreases before and after it
-        if x[i-1] < x[i] and x[i+1] < x[i]:
-            idx.append(i)
+
+        # starting or going up
+        if i == 0 or x[i] > x[i-1]:
+            up = True
+            bfr = [i]
+        # plateau
+        elif x[i] == x[i-1]:
+            if up:
+                bfr.append(i)
+        # going down
+        elif x[i] < x[i-1]:
+            up = False
+            idx += bfr
+            bfr = []
+        # end
+        if i == len(x) - 1:
+            if up:
+                idx += bfr                     
     return idx
diff --git a/test_maxima.py b/test_maxima.py
new file mode 100644
index 0000000..9bc67d5
--- /dev/null
+++ b/test_maxima.py
@@ -0,0 +1,28 @@
+from maxima import find_maxima
+import numpy as np
+
+def test_1():
+    assert find_maxima([0, 1, 2, 1, 2, 1, 0]) ==  [2, 4]
+
+def test_2():
+    assert find_maxima([2,1,0,1,4]) ==  [0, 4]
+
+def test_3():
+    assert find_maxima([np.sin(2*alpha) for alpha in np.linspace(0.0, 5.0, 100)]) ==  [16, 78]
+
+def test_4():
+    assert find_maxima([1, 2, 2, 3, 1]) ==  [3]
+
+
+def test_5():
+    assert find_maxima([1, 3, 2, 2, 1]) ==  [1]
+
+
+def test_6():
+    assert find_maxima([3, 2, 2, 3]) ==  [0, 3]
+
+def test_7():
+    assert find_maxima([1, 2, 2, 1]) ==  [1, 2]
+
+def test_8():
+    assert find_maxima([1, 2, 2, 2]) ==  [1, 2, 3]