diff --git a/src/libCom/osi/os/default/osiWireFormat.h b/src/libCom/osi/os/default/osiWireFormat.h
index 3ea8cf72d..7329df116 100644
--- a/src/libCom/osi/os/default/osiWireFormat.h
+++ b/src/libCom/osi/os/default/osiWireFormat.h
@@ -44,7 +44,7 @@ public:
         bool bigEndian () const { return ! littleEndian(); }
 private:
         unsigned uint;
-        unsigned char uchar[4];
+        unsigned char uchar[sizeof(unsigned)];
 };
 
 static const endianTest endianTester;