diff --git a/hscript/Error.hx b/hscript/Error.hx
index ba45c87..f2aef36 100644
--- a/hscript/Error.hx
+++ b/hscript/Error.hx
@@ -62,7 +62,7 @@ enum Error_
 	EInvalidEscape( s : String );
 }
 
-enum abstract ErrorMessage(Int) from Int to Int {
+enum abstract ErrorMessage(Expr.UInt8) from Expr.UInt8 to Expr.UInt8 {
     final INVALID_CHAR_CODE_MULTI;
     final FROM_CHAR_CODE_NON_INT;
     final EMPTY_INTERPOLATION;
diff --git a/hscript/Expr.hx b/hscript/Expr.hx
index 3fd2e84..dba62b1 100644
--- a/hscript/Expr.hx
+++ b/hscript/Expr.hx
@@ -21,6 +21,16 @@
  */
 package hscript;
 
+typedef Int8 = #if cpp cpp.Int8 #else Int #end;
+typedef Int16 = #if cpp cpp.Int16 #else Int #end;
+typedef Int32 = #if cpp cpp.Int32 #else Int #end;
+typedef Int64 = #if cpp cpp.Int64 #else Int #end;
+
+typedef UInt8 = #if cpp cpp.UInt8 #else Int #end;
+typedef UInt16 = #if cpp cpp.UInt16 #else Int #end;
+typedef UInt32 = #if cpp cpp.UInt32 #else Int #end;
+typedef UInt64 = #if cpp cpp.UInt64 #else Int #end;
+
 enum Const {
 	CInt( v : Int );
 	CFloat( f : Float );
@@ -30,12 +40,13 @@ enum Const {
 	#end
 }
 
-enum MapType {
-	IntMap;
-	StringMap;
-	EnumMap;
-	ObjectMap;
-	UnknownMap;
+enum abstract MapType(UInt8) {
+	var Null;
+	var IntMap;
+	var StringMap;
+	var EnumMap;
+	var ObjectMap;
+	var UnknownMap;
 }
 
 typedef Error = hscript.Error.Error_;
@@ -224,7 +235,7 @@ enum Binop {
 	OpNullCoal;
 }
 
-enum abstract Unop(Int) {
+enum abstract Unop(UInt8) {
 	/**
 		`++`
 	**/
@@ -352,13 +363,13 @@ typedef FieldDecl = {
 	var access : Array<FieldAccess>;
 }
 
-enum FieldAccess {
-	APublic;
-	APrivate;
-	AInline;
-	AOverride;
-	AStatic;
-	AMacro;
+enum abstract FieldAccess(UInt8) {
+	var APublic;
+	var APrivate;
+	var AInline;
+	var AOverride;
+	var AStatic;
+	var AMacro;
 }
 
 enum FieldKind {
diff --git a/hscript/Interp.hx b/hscript/Interp.hx
index 85872cd..02b6e99 100644
--- a/hscript/Interp.hx
+++ b/hscript/Interp.hx
@@ -45,7 +45,7 @@ private enum Stop {
 	SReturn;
 }
 
-enum abstract ScriptObjectType(Int) {
+enum abstract ScriptObjectType(UInt8) {
 	var SClass;
 	var SObject;
 	var SStaticClass;
diff --git a/hscript/Parser.hx b/hscript/Parser.hx
index 6b75dab..8fc997c 100644
--- a/hscript/Parser.hx
+++ b/hscript/Parser.hx
@@ -674,14 +674,14 @@ class Parser {
 
 				var t = b2i(isKeyString) + b2i(isKeyInt) + b2i(isKeyObject) + b2i(isKeyEnum);
 
-				var type:MapType = null;
+				var type:MapType = Null;
 				if(t != 1) type = UnknownMap;
 				else if(isKeyInt) type = IntMap;
 				else if(isKeyString) type = StringMap;
 				else if(isKeyEnum) type = EnumMap;
 				else if(isKeyObject) type = ObjectMap;
 
-				if(type == null)
+				if(type == Null)
 					error(EPreset(UNKNOWN_MAP_TYPE), p1, p1);
 
 				return parseExprNext(mk(EMapDecl(type, keys, values), p1));
diff --git a/hscript/Printer.hx b/hscript/Printer.hx
index f12393c..9ae6d9e 100644
--- a/hscript/Printer.hx
+++ b/hscript/Printer.hx
@@ -314,6 +314,7 @@ class Printer {
 							case EnumMap: add("EnumValue");
 							case IntMap: add("Int");
 							case UnknownMap: add("?");
+							case Null: add("Null");
 						}
 						add(", Dynamic>");
 					default: