diff --git a/extensions/openpower-pels/bcd_time.hpp b/extensions/openpower-pels/bcd_time.hpp
index 86d9f4e..72c5755 100644
--- a/extensions/openpower-pels/bcd_time.hpp
+++ b/extensions/openpower-pels/bcd_time.hpp
@@ -90,7 +90,7 @@
  *
  * @return Stream&
  */
-Stream& operator<<(Stream& s, BCDTime& time);
+Stream& operator<<(Stream& s, const BCDTime& time);
 
 } // namespace pels
 } // namespace openpower