diff --git a/lib/index.js b/lib/index.js
index <HASH>..<HASH> 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -16,9 +16,9 @@ function bnIsNegative(bn) {
   return bn.abs() !== bn;
 }
 
-// FIXME: this might not be the best idea
+// Limited to 53 bits (http://stackoverflow.com/questions/307179/what-is-javascripts-highest-integer-value-that-a-number-can-go-to-without-losin)
 function bnToInteger(bn) {
-  if (bn.bitLength() > 64)
+  if (bn.bitLength() > 53)
     throw new Error("BN is too big for Number: " + bn.bitLength());
   return parseInt(bn.toString());
 }
Limit BN to Number conversion to <I>bits (and not <I>bits)