diff --git a/lib/btc/amount.js b/lib/btc/amount.js
index f0df4f39..0e93a48d 100644
--- a/lib/btc/amount.js
+++ b/lib/btc/amount.js
@@ -488,7 +488,7 @@ Amount.parse = function parse(value, exp, num) {
 Amount.parseUnsafe = function parseUnsafe(value, exp, num) {
   if (typeof value === 'string') {
     assert(util.isFloat(value), 'Non-BTC value for conversion.');
-    value = parseFloat(value, 10);
+    value = parseFloat(value);
   } else {
     assert(util.isNumber(value), 'Non-BTC value for conversion.');
     assert(num, 'Cannot parse number.');
diff --git a/lib/utils/util.js b/lib/utils/util.js
index 248e6e42..18fa796f 100644
--- a/lib/utils/util.js
+++ b/lib/utils/util.js
@@ -392,6 +392,11 @@ util.isHex256 = function isHex256(hash) {
 
 /**
  * Test whether a string qualifies as a float.
+ *
+ * This is stricter than checking if the result of parseFloat() is NaN
+ * as, e.g. parseFloat successfully parses the string '1.2.3' as 1.2, and
+ * we also check that the value is a string.
+ *
  * @param {String?} value
  * @returns {Boolean}
  */