diff --git a/embedding/components/printingui/ipc/PPrintingTypes.ipdlh b/embedding/components/printingui/ipc/PPrintingTypes.ipdlh
index 1ac9c7f4cbff..f178906375d2 100644
--- a/embedding/components/printingui/ipc/PPrintingTypes.ipdlh
+++ b/embedding/components/printingui/ipc/PPrintingTypes.ipdlh
@@ -92,9 +92,20 @@ struct PrintData {
   CStringKeyValue[] GTKPrintSettings;
 
   /**
-   * TODO: OS X specific things - specifically, an array of names for the
-   * document to be supplied by nsIWebBrowserPrint::enumerateDocumentNames
+   * OS X specific things.
    */
+  nsString printJobName;
+  bool printAllPages;
+  bool mustCollate;
+  nsString disposition;
+  /** TODO: Is there an "unsigned short" primitive? **/
+  short pagesAcross;
+  short pagesDown;
+  nsString printTime;
+  bool detailedErrorReporting;
+  nsString faxNumber;
+  bool addHeaderAndFooter;
+  bool fileNameExtensionHidden;
 };
 
 } // namespace embedding
diff --git a/widget/nsPrintOptionsImpl.cpp b/widget/nsPrintOptionsImpl.cpp
index 371adf94b0dc..334af5b965fe 100644
--- a/widget/nsPrintOptionsImpl.cpp
+++ b/widget/nsPrintOptionsImpl.cpp
@@ -236,6 +236,17 @@ nsPrintOptions::SerializeToPrintData(nsIPrintSettings* aSettings,
   data->isIFrameSelected() = false;
   data->isRangeSelection() = false;
   // data->GTKPrintSettings() default-initializes
+  // data->printJobName() default-initializes
+  data->printAllPages() = true;
+  data->mustCollate() = false;
+  // data->disposition() default-initializes
+  data->pagesAcross() = 1;
+  data->pagesDown() = 1;
+  // data->printTime() default-initializes
+  data->detailedErrorReporting() = true;
+  // data->faxNumber() default-initializes
+  data->addHeaderAndFooter() = false;
+  data->fileNameExtensionHidden() = false;
 
   return NS_OK;
 }