diff --git a/04-fibonacci/index.js b/04-fibonacci/index.js
index 37c64cc..c2e3898 100644
--- a/04-fibonacci/index.js
+++ b/04-fibonacci/index.js
@@ -1,4 +1,11 @@
 export function fibonacci(value) {
   // implementar logica aqui
-  
+
+  let term = 0, actual = 1, next;
+  for (let i = 1; i <= value; i++) {
+    next = term + actual;
+    term = actual;
+    actual = next;
+  }
+  return term
 }
\ No newline at end of file