diff --git a/src/SerializedObject.cpp b/src/SerializedObject.cpp
index e77c756e1a..4178ef0087 100644
--- a/src/SerializedObject.cpp
+++ b/src/SerializedObject.cpp
@@ -226,7 +226,7 @@ void STObject::add(Serializer& s, bool withSigningFields) const
 		if (it.getSType() != STI_NOTPRESENT)
 		{
 			SField::ref fName = it.getFName();
-			if (withSigningFields || (fName == sfSignature) || (fName == sfSignatures))
+			if (withSigningFields || ((fName != sfSignature) && (fName != sfSignatures)))
 				fields.insert(std::make_pair(it.getFName().fieldCode, &it));
 		}
 	}