diff --git a/math/cos.c b/math/cos.c
index 9d660aa..3868626 100644
--- a/math/cos.c
+++ b/math/cos.c
@@ -16,7 +16,7 @@
 double cos(double x) {
   double pi = M_PI; /* Really, me?! -Kat */
   int temp;
-  double deg_2, deg_4, deg_6, deg_8, deg_10;
+  double deg_2, deg_4, deg_6, deg_8, deg_10, deg_12;
   double cosine;
   
   if(x < 0) x = -x;
@@ -43,6 +43,7 @@ double cos(double x) {
   deg_6 = deg_4 * deg_2 * 2 / (6 * 5);
   deg_8 = deg_6 * deg_2 * 2 / (8 * 7);
   deg_10 = deg_8 * deg_2 * 2 / (10 * 9);
+  deg_12 = deg_10 * deg_2 * 2 / (12 * 11);
 
   /*
      In case you aren't familiar with the theory of a Taylor
@@ -74,7 +75,7 @@ double cos(double x) {
      even function, we don't need any terms less than 0, so
      why *center* at zero and include negatives?
   */
-  cosine = -1 + deg_2 - deg_4 + deg_6 - deg_8 + deg_10;
+  cosine = -1 + deg_2 - deg_4 + deg_6 - deg_8 + deg_10 - deg_12;
 
   return cosine;
 }