diff --git a/packages/fcl-js/src/jstoken.pp b/packages/fcl-js/src/jstoken.pp
index 4554bcdb0c..853d6ae6ff 100644
--- a/packages/fcl-js/src/jstoken.pp
+++ b/packages/fcl-js/src/jstoken.pp
@@ -48,7 +48,8 @@ type
      tjsSWITCH,
      tjsTHIS, tjsTHROW, tjsTrue, tjsTRY, tjsTYPEOF,
      tjsVAR, tjsVOID,
-     tjsWHILE, tjsWITH
+     tjsWHILE, tjsWITH,
+     tjsAWAIT
    );
 
 const
@@ -83,7 +84,8 @@ const
      'switch',
      'this', 'throw', 'true', 'try', 'typeof',
      'var', 'void',
-     'while', 'with'
+     'while', 'with',
+     'await'
     );
 
 
diff --git a/packages/fcl-js/src/jstree.pp b/packages/fcl-js/src/jstree.pp
index 90dd4339cd..f8eacd3ae3 100644
--- a/packages/fcl-js/src/jstree.pp
+++ b/packages/fcl-js/src/jstree.pp
@@ -126,6 +126,7 @@ Type
   TJSFuncDef = Class(TJSObject)
   private
     FBody: TJSFunctionBody;
+    FIsAsync: Boolean;
     FIsEmpty: Boolean;
     FName: TJSString;
     FParams: TStrings;
@@ -137,6 +138,7 @@ Type
     Property Body : TJSFunctionBody Read FBody Write FBody; // can be nil
     Property Name : TJSString Read FName Write FName;
     Property IsEmpty : Boolean Read FIsEmpty Write FIsEmpty;
+    Property IsAsync : Boolean Read FIsAsync Write FIsAsync;
   end;
 
   { TJSElement }
@@ -383,6 +385,13 @@ Type
     Class function PrefixOperatorToken : tjsToken; override;
   end;
 
+  { TJSAwaitExpression - e.g. 'await A' }
+
+  TJSAwaitExpression = Class(TJSUnaryExpression)
+  Public
+    Class function PrefixOperatorToken : tjsToken; Override;
+  end;
+
   { TJSUnaryPrePlusPlusExpression - e.g. '++A' }
 
   TJSUnaryPrePlusPlusExpression = Class(TJSUnaryExpression)
@@ -1514,6 +1523,13 @@ begin
   Result:=tjsTypeOf;
 end;
 
+{ TJSAwaitExpression }
+
+class function TJSAwaitExpression.PrefixOperatorToken: tjsToken;
+begin
+  Result:=tjsAwait;
+end;
+
 { TJSUnaryDeleteExpression }
 
 Class function TJSUnaryDeleteExpression.PrefixOperatorToken : tjsToken;
@@ -1705,7 +1721,7 @@ begin
   else
     begin
     Result:=TokenInfos[t];
-    if t in [tjsTypeOf,tjsVoid,tjsDelete,tjsThrow] then
+    if t in [tjsTypeOf,tjsVoid,tjsDelete,tjsThrow,tjsAwait] then
       Result:=Result+' ';
     end;
 end;
diff --git a/packages/fcl-js/src/jswriter.pp b/packages/fcl-js/src/jswriter.pp
index eb02b24896..b1d167179e 100644
--- a/packages/fcl-js/src/jswriter.pp
+++ b/packages/fcl-js/src/jswriter.pp
@@ -927,6 +927,8 @@ Var
 begin
   LastEl:=Writer.CurElement;
   C:=(woCompact in Options);
+  if fd.IsAsync then
+    Write('async ');
   Write('function ');
   If (FD.Name<>'') then
     Write(FD.Name);
diff --git a/packages/fcl-js/tests/tcwriter.pp b/packages/fcl-js/tests/tcwriter.pp
index 0bf95f71e6..6db7186936 100644
--- a/packages/fcl-js/tests/tcwriter.pp
+++ b/packages/fcl-js/tests/tcwriter.pp
@@ -167,6 +167,7 @@ type
     Procedure TestFunctionDefBody1Compact;
     Procedure TestFunctionDefBody2;
     Procedure TestFunctionDefBody2Compact;
+    Procedure TestFunctionDefAsync;
     Procedure TestTryCatch;
     Procedure TestTryCatchCompact;
     Procedure TestTryFinally;
@@ -193,6 +194,7 @@ type
     Procedure TestUnaryDelete;
     Procedure TestUnaryVoid;
     Procedure TestUnaryTypeOf;
+    Procedure TestUnaryAwait;
     Procedure TestPrefixPlusPLus;
     Procedure TestPrefixMinusMinus;
     Procedure TestUnaryMinus;
@@ -347,6 +349,11 @@ begin
   TestUnary('typeof expresssion',TJSUnaryTypeOfExpression,'typeof a');
 end;
 
+procedure TTestExpressionWriter.TestUnaryAwait;
+begin
+  TestUnary('await expresssion',TJSAwaitExpression,'await a');
+end;
+
 procedure TTestExpressionWriter.TestPrefixPlusPLus;
 begin
   TestUnary('prefix ++ expresssion',TJSUnaryPrePlusPlusExpression,'++a');
@@ -1902,6 +1909,21 @@ begin
   AssertWrite('Function, 2 statements, compact','function a(b) {b=b*10; return b}',FD);
 end;
 
+procedure TTestStatementWriter.TestFunctionDefAsync;
+
+Var
+  FD : TJSFunctionDeclarationStatement;
+
+begin
+  FD:=TJSFunctionDeclarationStatement.Create(0,0);
+  FD.AFunction:=TJSFuncDef.Create;
+  FD.AFunction.IsAsync:=true;
+  FD.AFunction.Name:='a';
+  AssertWrite('Async function',
+     'async function a() {'+sLineBreak
+    +'}',FD);
+end;
+
 procedure TTestStatementWriter.TestTryCatch;
 
 Var