diff --git a/oscar64/Declaration.cpp b/oscar64/Declaration.cpp
index cc45292..c7e2c4a 100644
--- a/oscar64/Declaration.cpp
+++ b/oscar64/Declaration.cpp
@@ -502,8 +502,16 @@ Expression* Expression::ConstantFold(Errors * errors, LinkerSection * dataSectio
 			{
 				Expression* ex = new Expression(mLocation, EX_CONSTANT);
 				Declaration* dec = new Declaration(mLocation, DT_CONST_INTEGER);
-				dec->mBase = mLeft->mDecValue->mBase;
+
 				dec->mInteger = ~mLeft->mDecValue->mInteger;
+				if (mLeft->mDecValue->mBase->mSize <= 2)
+				{
+					dec->mInteger &= 0xffff;
+					dec->mBase = TheUnsignedIntTypeDeclaration;
+				}
+				else
+					dec->mBase = TheUnsignedLongTypeDeclaration;
+
 				ex->mDecValue = dec;
 				ex->mDecType = dec->mBase;
 				return ex;
diff --git a/oscar64/Parser.cpp b/oscar64/Parser.cpp
index 4cb7cd7..70e091a 100644
--- a/oscar64/Parser.cpp
+++ b/oscar64/Parser.cpp
@@ -7281,6 +7281,18 @@ Expression* Parser::ParsePrefixExpression(bool lhs)
 			{
 				nexp->mDecType = TheUnsignedCharTypeDeclaration;
 			}
+			else if (nexp->mToken == TK_BINARY_AND)
+			{
+				if (nexp->mDecType->mFlags & DTF_SIGNED)
+				{
+					if (nexp->mDecType->mSize == 4)
+						nexp->mDecType = TheUnsignedLongTypeDeclaration;
+					else
+						nexp->mDecType = TheUnsignedIntTypeDeclaration;
+				}
+				else
+					nexp->mDecType = nexp->mLeft->mDecType;
+			}
 			else
 				nexp->mDecType = nexp->mLeft->mDecType;
 		}