diff --git a/fib.py b/fib.py
index 50722c2..7ef977e 100644
--- a/fib.py
+++ b/fib.py
@@ -8,6 +8,8 @@
 def fibonacci(position):
   if(position == 1 or position == 2):
     return 1
+  else if position <0:
+    return fibonacci(position - 1) - fibonacci(position - 2)
   return fibonacci(position - 1) + fibonacci(position - 2)