diff --git a/modules/product/commerce_product.module b/modules/product/commerce_product.module
index 5a2c186..791f2b2 100644
--- a/modules/product/commerce_product.module
+++ b/modules/product/commerce_product.module
@@ -691,7 +691,7 @@ function commerce_product_validate_sku_unique($sku, $product_id) {
  */
 function commerce_product_validate_sku($sku) {
   // Do not allow commas in a SKU.
-  if (strpos($sku, ',')) {
+  if (strpos($sku, ',') !== FALSE) {
     return FALSE;
   }