diff --git a/lib/rex/peparsey/pebase.rb b/lib/rex/peparsey/pebase.rb
index f37b3ca..a19824a 100644
--- a/lib/rex/peparsey/pebase.rb
+++ b/lib/rex/peparsey/pebase.rb
@@ -492,8 +492,8 @@ def initialize(_name, _ordinal, _rva)
     [ 'uint64v', 'ImageBase',                    0 ],
     [ 'uint32v', 'SectionAlignment',             0 ],
     [ 'uint32v', 'FileAlignment',                0 ],
-    [ 'uint16v', 'MajorOperatingsystemVersion',  0 ],
-    [ 'uint16v', 'MinorOperatingsystemVersion',  0 ],
+    [ 'uint16v', 'MajorOperatingSystemVersion',  0 ],
+    [ 'uint16v', 'MinorOperatingSystemVersion',  0 ],
     [ 'uint16v', 'MajorImageVersion',            0 ],
     [ 'uint16v', 'MinorImageVersion',            0 ],
     [ 'uint16v', 'MajorSubsystemVersion',        0 ],