diff --git a/test/index.html b/test/index.html
index b49d07047..8f5bfde82 100644
--- a/test/index.html
+++ b/test/index.html
@@ -146,7 +146,9 @@
 				if (!window.Float64Array && window.Uint8Array) {
 					Float64Array = (function() {
 						function Float64Array(buffer, byteOffset, length) {
-							return new Uint8Array(buffer, byteOffset || 0, length || buffer.byteLength);
+							return arguments.length == 1
+								? new Uint8Array(buffer)
+								: new Uint8Array(buffer, byteOffset || 0, length || buffer.byteLength);
 						}
 						setProperty(Float64Array, 'BYTES_PER_ELEMENT', 8);
 						setProperty(Float64Array, 'toString', createToString('Float64Array'));
diff --git a/test/test.js b/test/test.js
index 1fcc5d65b..abc4487af 100644
--- a/test/test.js
+++ b/test/test.js
@@ -413,7 +413,9 @@
     if (!root.Float64Array) {
       setProperty(root, 'Float64Array', (function() {
         function Float64Array(buffer, byteOffset, length) {
-          return new Uint8Array(buffer, byteOffset || 0, length || buffer.byteLength);
+          return arguments.length == 1
+            ? new Uint8Array(buffer)
+            : new Uint8Array(buffer, byteOffset || 0, length || buffer.byteLength);
         }
         setProperty(Float64Array, 'BYTES_PER_ELEMENT', 8);
         setProperty(Float64Array, 'toString', createToString('Float64Array'));