diff --git a/src/pivot.coffee b/src/pivot.coffee
index 45c28261..9c2fbb74 100644
--- a/src/pivot.coffee
+++ b/src/pivot.coffee
@@ -19,7 +19,7 @@ callWithJQuery ($) ->
         x1 = x[0]
         x2 = if x.length > 1 then  decimalSep + x[1] else ''
         rgx = /(\d+)(\d{3})/
-        x1 = x1.replace(rgx, '$1' + thousandsSep + '$2') while rgx.test(x1)
+        x1 = x1.replace(rgx, '$1' + thousandsSep + '$2') while rgx.test(x1) if thousandsSep
         return x1 + x2
 
     numberFormat = (opts) ->
diff --git a/tests/pivot_spec.coffee b/tests/pivot_spec.coffee
index 3028f86c..08adfd45 100644
--- a/tests/pivot_spec.coffee
+++ b/tests/pivot_spec.coffee
@@ -532,6 +532,11 @@ describe "$.pivotUtilities", ->
             expect nf 1234567.89123456
             .toEqual "1a234a567b89"
 
+        it "adds blank thousands separator", ->
+            nf = numberFormat(thousandsSep: "", decimalSep: "b")
+            expect nf 1234567.89123456
+            .toEqual "1234567b89"
+
         it "adds prefixes and suffixes", ->
             nf = numberFormat(prefix: "a", suffix: "b")
             expect nf 1234567.89123456