diff --git a/packages/fcl-js/src/jssrcmap.pas b/packages/fcl-js/src/jssrcmap.pas
index b2fc66817c..3d3076e956 100644
--- a/packages/fcl-js/src/jssrcmap.pas
+++ b/packages/fcl-js/src/jssrcmap.pas
@@ -68,6 +68,11 @@ uses
   ;
 {$ENDIF FPC_DOTTEDUNITS}
 
+{$IFDEF PAS2JS}
+Type
+  AnsiString = String;
+{$ENDIF}
+
 const
   Base64Chars = AnsiString('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/');
 
diff --git a/packages/fcl-js/src/jswriter.pp b/packages/fcl-js/src/jswriter.pp
index f846f238b1..66eb6fb9c4 100644
--- a/packages/fcl-js/src/jswriter.pp
+++ b/packages/fcl-js/src/jswriter.pp
@@ -39,6 +39,7 @@ uses
 Type
   {$ifdef pas2js}
   TJSWriterString = UnicodeString;
+  AnsiChar = char;
   {$else}
   TJSWriterString = AnsiString;
   {$endif}
@@ -2283,11 +2284,15 @@ end;
 function TTextWriter.WriteLn(const S: TJSWriterString): Integer;
 begin
   Result:=Write(S);
+{$IFDEF PAS2JS}  
+  Result:=Result+Write(LineBreak);
+{$ELSE}
 {$IF SIZEOF(Char)=1}
   Result:=Result+Write(LineBreak);
 {$else}
   Result:=Result+Write(UTF8Encode(LineBreak));
 {$ENDIF}
+{$ENDIF}
 end;
 
 function TTextWriter.Write(const Fmt: TJSWriterString;
diff --git a/packages/fcl-passrc/src/pasresolveeval.pas b/packages/fcl-passrc/src/pasresolveeval.pas
index 6f114ab34c..30c9276064 100644
--- a/packages/fcl-passrc/src/pasresolveeval.pas
+++ b/packages/fcl-passrc/src/pasresolveeval.pas
@@ -4295,7 +4295,7 @@ var
   end;
 {$ENDIF}
 
-  procedure AddSrc(h: AnsiString);
+  procedure AddSrc(h: {$IFDEF PAS2JS}String{$ELSE}AnsiString{$ENDIF});
   {$ifdef FPC_HAS_CPSTRING}
   var
     ValueAnsi: TResEvalString;
diff --git a/packages/fcl-passrc/src/pasresolver.pp b/packages/fcl-passrc/src/pasresolver.pp
index ec29a1b8a9..3ffbad8a7d 100644
--- a/packages/fcl-passrc/src/pasresolver.pp
+++ b/packages/fcl-passrc/src/pasresolver.pp
@@ -15029,7 +15029,11 @@ begin
     else
       if (l=3) and (Value[3]='''') then
         if Ord(Value[2])<128 then
+          {$IFNDEF PAS2JS}
           Result:=btAnsiChar // e.g. 'a'
+          {$ELSE}
+          Result:=btWideChar           
+          {$ENDIF}
         else
           Result:=btWideChar; // e.g. 'a'
     end;
diff --git a/packages/fcl-passrc/src/pastree.pp b/packages/fcl-passrc/src/pastree.pp
index 1a6c82123d..c277a80871 100644
--- a/packages/fcl-passrc/src/pastree.pp
+++ b/packages/fcl-passrc/src/pastree.pp
@@ -4702,7 +4702,7 @@ end;
 function TPasVariable.GetDeclaration (full : boolean) : TPasTreeString;
 
 Const
- Seps : Array[Boolean] of AnsiChar = ('=',':');
+ Seps : Array[Boolean] of Char = ('=',':');
 
 begin
   If Assigned(VarType) then
diff --git a/packages/fcl-passrc/src/pparser.pp b/packages/fcl-passrc/src/pparser.pp
index c6f9937b7b..3c35a8cd9f 100644
--- a/packages/fcl-passrc/src/pparser.pp
+++ b/packages/fcl-passrc/src/pparser.pp
@@ -1539,6 +1539,8 @@ function TPasParser.TryErrorRecovery(const aContext: TRecoveryContext): boolean;
 
 var
   StopAt : TTokens;
+  Obj : TObject;
+  
 begin
   Inc(FErrorCount);
   Result:=FErrorCount<FMaxErrorCount;
@@ -1556,7 +1558,10 @@ begin
   // Destroy element if engine allows it.
   if Assigned(aContext.Element) then
     if Engine.HandleResultOnError(aContext.Element) then
-      aContext.Element.Free;
+      begin
+      Obj:=aContext.Element;
+      Obj.Free;
+      end;
   // ParseExc recorded the error message, force display
   LogLastMessage;
   StopAt:=aContext.RestartTokens;
diff --git a/packages/fcl-passrc/src/pscanner.pp b/packages/fcl-passrc/src/pscanner.pp
index b5b591cbf3..68686b4bfc 100644
--- a/packages/fcl-passrc/src/pscanner.pp
+++ b/packages/fcl-passrc/src/pscanner.pp
@@ -127,13 +127,20 @@ resourcestring
   SWarnIgnoringLinkLib = 'Ignoring LINKLIB directive %s -> %s (Options: %s)';
 
 type
-  {$IF NOT DECLARED(RTLSTRING)}
-    RTLString = ansistring;
+  {$IFDEF PAS2JS}
+    RTLString = string;
     TRTLStringDynArray = array of RTLString;
+    TPasScannerString = String;
+    AnsiChar = Char;
+  {$ELSE}
+    {$IF NOT DECLARED(RTLSTRING) }
+      RTLString = ansistring;
+      TRTLStringDynArray = array of RTLString;
+    {$ENDIF}
+    // String used for scanning
+    TPasScannerString = RawByteString;
   {$ENDIF}
 
-  // String used for scanning
-  TPasScannerString = RawByteString;
   // String used for interfacing with PasTree
   TPasTreeString = String;
 
@@ -490,7 +497,11 @@ type
 
   TStreamLineReader = class(TLineReader)
   private
+    {$ifndef pas2js}
     FContent: RawByteString;
+    {$ELSE}
+    FContent: String;
+    {$ENDIF}
     FPos : Integer;
   public
     {$ifdef HasStreams}
@@ -2828,10 +2839,14 @@ end;
 
 procedure TStreamLineReader.InitFromString(const s: TPasScannerString);
 begin
+{$IFDEF PAS2JS}
+  FContent:=S;
+{$ELSE}
 {$IF SIZEOF(CHAR)=2}
   FContent:=UTF8Encode(s);
 {$ELSE}
   FContent:=S;
+{$ENDIF}
 {$ENDIF}
   FPos:=0;
 end;
@@ -3728,7 +3743,7 @@ begin
         else
           begin
           // skip identifier
-          if FTokenPos[0]='@' then
+          if {$ifdef UsePChar}FTokenPos[0]='@'{$ELSE} (FTokenPos<=l) and (s[FTokenPos]='@'){$ENDIF} then
             inc(FTokenPos);
           while {$ifdef UsePChar}FTokenPos[0] in IdentChars{$else}(FTokenPos<=l) and (s[FTokenPos] in IdentChars){$endif} do
             inc(FTokenPos);
@@ -5828,11 +5843,15 @@ end;
 
 function TPascalScanner.GetTokenString: TPasTreeString;
 begin
+{$IFDEF PAS2JS}
+  Result:=RawCurTokenString;
+{$ELSE}
 {$IF SIZEOF(Char)=2}
   Result:=UTF8Decode(RawCurTokenString);
 {$ELSE}
   Result:=RawCurTokenString;
 {$ENDIF}
+{$ENDIF}
 end;
 
 function TPascalScanner.IndexOfWarnMsgState(Number: integer; InsertPos: boolean
diff --git a/packages/pastojs/src/pas2jslogger.pp b/packages/pastojs/src/pas2jslogger.pp
index 4c117039e9..d7dd00f45f 100644
--- a/packages/pastojs/src/pas2jslogger.pp
+++ b/packages/pastojs/src/pas2jslogger.pp
@@ -76,7 +76,8 @@ const
 
 type
   {$IFDEF Pas2JS}
-
+  Ansistring = String;
+  
   { TPas2jsStream }
 
   TPas2jsStream = class