diff --git a/include/unotools/progresshandlerwrap.hxx b/include/unotools/progresshandlerwrap.hxx
index d6da3c9dc62a..8ed4b7815d1f 100644
--- a/include/unotools/progresshandlerwrap.hxx
+++ b/include/unotools/progresshandlerwrap.hxx
@@ -33,7 +33,7 @@ class UNOTOOLS_DLLPUBLIC ProgressHandlerWrap : public ::cppu::WeakImplHelper< cs
     css::uno::Reference< css::task::XStatusIndicator > m_xStatusIndicator;
 
 public:
-    ProgressHandlerWrap( css::uno::Reference< css::task::XStatusIndicator > xSI );
+    ProgressHandlerWrap( css::uno::Reference< css::task::XStatusIndicator > const & xSI );
 
     // XProgressHandler
     virtual void SAL_CALL push( const css::uno::Any& Status )
diff --git a/unotools/source/ucbhelper/progresshandlerwrap.cxx b/unotools/source/ucbhelper/progresshandlerwrap.cxx
index b84882fdffe4..f3edf6185dfd 100644
--- a/unotools/source/ucbhelper/progresshandlerwrap.cxx
+++ b/unotools/source/ucbhelper/progresshandlerwrap.cxx
@@ -26,7 +26,7 @@ using namespace ::com::sun::star::uno;
 using namespace ::com::sun::star::task;
 using namespace ::com::sun::star::ucb;
 
-ProgressHandlerWrap::ProgressHandlerWrap( css::uno::Reference< css::task::XStatusIndicator > xSI )
+ProgressHandlerWrap::ProgressHandlerWrap( css::uno::Reference< css::task::XStatusIndicator > const & xSI )
 : m_xStatusIndicator( xSI )
 {
 }
diff --git a/unotools/source/ucbhelper/ucblockbytes.cxx b/unotools/source/ucbhelper/ucblockbytes.cxx
index a87ef191e08a..f894c1cf7e1a 100644
--- a/unotools/source/ucbhelper/ucblockbytes.cxx
+++ b/unotools/source/ucbhelper/ucblockbytes.cxx
@@ -220,8 +220,8 @@ class Moderator
 
 public:
     Moderator(
-        Reference < XContent >& xContent,
-        Reference < XInteractionHandler >& xInteract,
+        Reference < XContent > const & xContent,
+        Reference < XInteractionHandler > const & xInteract,
         const Command& rArg
     )
         throw(
@@ -495,8 +495,8 @@ ModeratorsInteractionHandler::handle(
 }
 
 Moderator::Moderator(
-    Reference < XContent >& xContent,
-    Reference < XInteractionHandler >& xInteract,
+    Reference < XContent > const & xContent,
+    Reference < XInteractionHandler > const & xInteract,
     const Command& rArg
 )
     throw(
@@ -720,10 +720,10 @@ static bool UCBOpenContentSync_(
 
 static bool UCBOpenContentSync(
     const UcbLockBytesRef& xLockBytes,
-    Reference < XContent > xContent,
+    Reference < XContent > const & xContent,
     const Command& rArg,
     const Reference < XInterface >& xSink,
-    Reference < XInteractionHandler > xInteract )
+    Reference < XInteractionHandler > const & xInteract )
 {
     // http protocol must be handled in a special way:
     //        during the opening process the input stream may change