diff --git a/spec/quantitiesSpec.js b/spec/quantitiesSpec.js
index 6ee20da..11065c1 100644
--- a/spec/quantitiesSpec.js
+++ b/spec/quantitiesSpec.js
@@ -219,13 +219,9 @@ describe("js-quantities", function() {
       expect(function() { Qty("mmm"); }).toThrow("Unit not recognized");
     });
 
-    it("should throw error when passing an empty string", function() {
-      expect(
-        function() { Qty(""); }
-      ).toThrow("Unit not recognized");
-      expect(
-        function() { Qty("   "); }
-      ).toThrow("Unit not recognized");
+    it("should accept empty string as unitless 1", function() {
+      expect(Qty("").same(Qty("1"))).toBe(true);
+      expect(Qty("   ").same(Qty("1"))).toBe(true);
     });
 
     it("should throw error when passing a null value", function() {
diff --git a/src/quantities.js b/src/quantities.js
index b020386..02ec20a 100644
--- a/src/quantities.js
+++ b/src/quantities.js
@@ -671,9 +671,6 @@ SOFTWARE.
       val = val.toString();
     }
     val = val.trim();
-    if (val.length === 0) {
-      throw new QtyError("Unit not recognized");
-    }
 
     var result = QTY_STRING_REGEX.exec(val);
     if (!result) {