diff --git a/client/mysqltest.cc b/client/mysqltest.cc
index 107848d6777..89b9c78a049 100644
--- a/client/mysqltest.cc
+++ b/client/mysqltest.cc
@@ -1496,12 +1496,15 @@ void show_diff(DYNAMIC_STRING* ds,
   /* determine if we have diff on Windows
      needs special processing due to return values
      on that OS
+     This test is only done on Windows since it's only needed there
+     in order to correctly detect non-availibility of 'diff', and
+     the way it's implemented does not work with default 'diff' on Solaris.
   */
 #ifdef __WIN__
   have_diff = diff_check();
 #else
   have_diff = 1;
-#endif  
+#endif
 
   if (have_diff)
   {