diff --git a/sql/field.cc b/sql/field.cc
index ce1b1fc6eb0..a9b5fedda2d 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -8408,6 +8408,8 @@ uchar *Field_enum::pack(uchar *to, const uchar *from,
   default:
     DBUG_ASSERT(0);
   }
+  MY_ASSERT_UNREACHABLE();
+  DBUG_RETURN(NULL);
 }
 
 const uchar *Field_enum::unpack(uchar *to, const uchar *from,
@@ -8430,6 +8432,8 @@ const uchar *Field_enum::unpack(uchar *to, const uchar *from,
   default:
     DBUG_ASSERT(0);
   }
+  MY_ASSERT_UNREACHABLE();
+  DBUG_RETURN(NULL);
 }