diff --git a/lib/ex_xirr.ex b/lib/ex_xirr.ex
index 33103db..65bc2ce 100644
--- a/lib/ex_xirr.ex
+++ b/lib/ex_xirr.ex
@@ -185,6 +185,9 @@ defmodule ExXirr do
   defp calculate(:xirr, _, _, rate, _) when rate > 1_000_000_000,
     do: {:error, "Converged on infinity."}
 
+  defp calculate(:xirr, _, _, rate, _) when rate > -1_000_000,
+    do: {:error, "Converged on infinity."}
+
   defp calculate(:xirr, _, acc, rate, _) when acc in [-0.0, +0.0], do: {:ok, Float.round(rate, 8)}
 
   defp calculate(:xirr, _, _, -1.0, _), do: {:error, "Could not converge."}