--- client/mysql_upgrade.c
+++ client/mysql_upgrade.c
@@ -584,6 +584,15 @@ int main(int argc, char **argv)
   ret= system(cmdline.str);
   if (ret)
   {
+#if defined(WIFEXITED) && defined(WEXITSTATUS)
+    /* on unix, system() returns the value returned by wait(), _not_ the exit
+     * status */
+    if (WIFEXITED(ret))
+      ret= WEXITSTATUS(ret);
+    else
+      /* this could be handled better, but it's a quite unlikely case */
+      ret= 1;
+#endif
     fprintf(stderr, "Error executing '%s'\n", cmdline.str);
     goto error;
   }
@@ -640,7 +649,14 @@ fix_priv_tables:
 
   ret= system(cmdline.str);
   if (ret)
+  {
     fprintf(stderr, "Error executing '%s'\n", cmdline.str);
+    fputs("You can safely ignore all 'Duplicate column' and 'Unknown column' errors\n",
+        stderr);
+    fputs("because these just mean that your tables are already up to date.\n",
+        stderr);
+    ret= 0;
+  }
 
 error:
   dynstr_free(&cmdline);