diff --git a/reed_solomon.py b/reed_solomon.py
index b2a2c9f07a9ead436128557969c09bb29199d3a7..cd7c2f3a8044c1e6957257beb014d0caa310375e 100644
--- a/reed_solomon.py
+++ b/reed_solomon.py
@@ -36,4 +36,10 @@ def lagrange_compute(l: list) -> polynome:
 	return poly
 
 def check_nb_error(l: list, p: polynome) -> int:
-	pass
+	
+	nbr_error = 0
+	for _, item in enumerate(l):
+		if (item % p.prime_mod) != (p.evaluate(_) % p.prime_mod):
+			print(f"DEBUG PURPOSES ONLY {item} != p.evaluate({_}) = {p.evaluate(_)}")
+			nbr_error += 1
+	return nbr_error