diff --git a/modules/product_reference/commerce_product_reference.module b/modules/product_reference/commerce_product_reference.module
index a2d7fc5..f05cd8a 100644
--- a/modules/product_reference/commerce_product_reference.module
+++ b/modules/product_reference/commerce_product_reference.module
@@ -1090,7 +1090,9 @@ function commerce_product_line_item_populate($line_item, $product) {
 
   // Set the unit price on the line item object if the product has a value in
   // its commerce_price field.
-  $line_item->commerce_unit_price = $product->commerce_price;
+  if (!empty($product->commerce_price)) {
+    $line_item->commerce_unit_price = $product->commerce_price;
+  }
 
   if (!is_null($line_item_wrapper->commerce_unit_price->value())) {
     // Add the base price to the components array.