--- src/doc/PdfPage.cpp
+++ src/doc/PdfPage.cpp
@@ -443,7 +443,7 @@
     }
 }
 
-void PdfPage::DeleteAnnotation( const PdfReference & ref )
+void PdfPage::DeleteAnnotation( const PdfReference ref )
 {
     PdfAnnotation*     pAnnot;
     PdfArray::iterator it;
--- src/doc/PdfPage.h
+++ src/doc/PdfPage.h
@@ -223,7 +223,7 @@
      *
      *  \see GetNumAnnots
      */
-    void DeleteAnnotation( const PdfReference & ref );
+    void DeleteAnnotation( const PdfReference ref );
 
     /** 
      * \returns the number of PdfFields on this page.