diff --git a/xmlsecurity/source/dialogs/certificateviewer.cxx b/xmlsecurity/source/dialogs/certificateviewer.cxx
index b75e37e96c5a..27e0cbcba048 100644
--- a/xmlsecurity/source/dialogs/certificateviewer.cxx
+++ b/xmlsecurity/source/dialogs/certificateviewer.cxx
@@ -171,9 +171,9 @@ CertificateViewerGeneralTP::CertificateViewerGeneralTP( Window* _pParent, Certif
     utl::typeConvert( xCert->getNotValidBefore(), aDateTimeStart );
     utl::typeConvert( xCert->getNotValidAfter(), aDateTimeEnd );
     OUString sText = maValidDateFI.GetText();
-    sText.replaceFirst( "%SDATE%",
+    sText = sText.replaceFirst( "%SDATE%",
         GetSettings().GetUILocaleDataWrapper().getDate( aDateTimeStart.GetDate() ) );
-    sText.replaceFirst( "%EDATE%",
+    sText = sText.replaceFirst( "%EDATE%",
         GetSettings().GetUILocaleDataWrapper().getDate( aDateTimeEnd.GetDate() ) );
     maValidDateFI.SetText( sText );