diff --git a/TOOLS/mphelp_check.py b/TOOLS/mphelp_check.py
index 92c54cb70a..00e6bc6746 100755
--- a/TOOLS/mphelp_check.py
+++ b/TOOLS/mphelp_check.py
@@ -56,7 +56,7 @@ if len(sys.argv) < 3:
     sys.exit(1)
 i = 1
 show_missing = False
-if sys.argv[i] == ( '--missing' or '-missing' ):
+if sys.argv[i] in ( '--missing', '-missing' ):
     show_missing = True
     i = 2
 base = parse(sys.argv[i])