diff --git a/algorithms/stack/is_sorted.py b/algorithms/stack/is_sorted.py
index 8824dfa95..0a69d83f9 100644
--- a/algorithms/stack/is_sorted.py
+++ b/algorithms/stack/is_sorted.py
@@ -13,15 +13,15 @@ def is_sorted(stack):
     storage_stack = []
     for i in range(len(stack)):
         if len(stack) == 0:
-            return True
+            break
         first_val = stack.pop()
         if len(stack) == 0:
-            return True
+            break
         second_val = stack.pop()
         if first_val < second_val:
             return False
         storage_stack.append(first_val)
-        storage_stack.append(second_val)
+        stack.append(second_val)
 
     # Backup stack
     for i in range(len(storage_stack)):
diff --git a/tests/test_stack.py b/tests/test_stack.py
index d04b27f14..78822bc17 100644
--- a/tests/test_stack.py
+++ b/tests/test_stack.py
@@ -25,6 +25,7 @@ def test_is_sorted(self):
         # Test case: bottom [6, 3, 5, 1, 2, 4] top
         self.assertFalse(is_sorted([6, 3, 5, 1, 2, 4]))
         self.assertTrue(is_sorted([1, 2, 3, 4, 5, 6]))
+        self.assertFalse(is_sorted([3, 4, 7, 8, 5, 6]))
 
     def test_remove_min(self):
         # Test case: bottom [2, 8, 3, -6, 7, 3] top