diff --git a/array.lua b/array.lua
index afdc0b1..ab29ea6 100644
--- a/array.lua
+++ b/array.lua
@@ -153,4 +153,12 @@ function Array:equals(array)
   return getmetatable(array) == Array 
     and #self == #array
     and equal_values 
+end
+
+function Array:sum()
+  local total = 0
+  for _, value in ipairs(self) do
+    total = total + value
+  end
+  return total
 end
\ No newline at end of file
diff --git a/scale.lua b/scale.lua
index 640d23d..057e98e 100644
--- a/scale.lua
+++ b/scale.lua
@@ -82,6 +82,10 @@ function Scale.c_major()
   })
 end
 
+function Scale:count_alterations()
+  return self.notes:map(function(n) return n.alteration end):sum()
+end
+
 --[[
   Warning: only works for ionian scales
 ]]
@@ -110,12 +114,14 @@ end
   Warning: only works for ionian scales
 ]]
 function Scale:circle_of_5ths_rotate(iterations)
-  if(iterations == 0) then
+  local total_alterations = self:count_alterations()+iterations
+  local rotation = ( (total_alterations + 5) % 12 ) - 5
+  if(rotation == 0) then
     return self
-  elseif(iterations < 0) then
-    return self:to_the_left_on_circle_of_5ths(-iterations)
-  elseif(iterations > 0) then
-    return self:to_the_right_on_circle_of_5ths(iterations)
+  elseif(rotation < 0) then
+    return self:to_the_left_on_circle_of_5ths(-rotation)
+  elseif(rotation > 0) then
+    return self:to_the_right_on_circle_of_5ths(rotation)
   else
     return "Error"
   end
diff --git a/test/test_scale.lua b/test/test_scale.lua
index 3a2e9c6..132c015 100644
--- a/test/test_scale.lua
+++ b/test/test_scale.lua
@@ -359,4 +359,13 @@ function TestScale:testGetDistance()
   luaunit.assertEquals(f_sharp_maj:get_distance(g_flat_min), 2)
   luaunit.assertEquals(f_sharp_maj:get_distance(d_sharp_min), 0)
   luaunit.assertEquals(f_sharp_maj:get_distance(d_sharp_min_harm), 1)
-end
\ No newline at end of file
+end
+
+function TestScale:test_c5ths_rotate()
+  local c_major = Scale.c_major()
+  luaunit.assertEquals(c_major:circle_of_5ths_rotate(12), c_major:circle_of_5ths_rotate(0))
+  luaunit.assertEquals(c_major:circle_of_5ths_rotate(8), c_major:circle_of_5ths_rotate(-4))
+  luaunit.assertEquals(c_major:circle_of_5ths_rotate(-8), c_major:circle_of_5ths_rotate(4))
+  luaunit.assertEquals(c_major:circle_of_5ths_rotate(123), c_major:circle_of_5ths_rotate(3))
+  luaunit.assertEquals(c_major:circle_of_5ths_rotate(-123), c_major:circle_of_5ths_rotate(-3))
+end