diff --git a/components/codetools/finddeclarationtool.pas b/components/codetools/finddeclarationtool.pas
index 8e8ac3c8cb..128f401ff0 100644
--- a/components/codetools/finddeclarationtool.pas
+++ b/components/codetools/finddeclarationtool.pas
@@ -9527,6 +9527,11 @@ begin
           if ParamList.Count<>1 then exit;
           Result:=ParamList.Items[0];
         end
+        else if (CompareIdentifiers(IdentPos,'IFTHEN')=0) then
+        begin
+          if ParamList.Count<>3 then exit;
+          Result:=ParamList.Items[1]; // ifthen sets the result based on the second parameter
+        end
         else if (CompareIdentifiers(IdentPos,'LOW')=0)
              or (CompareIdentifiers(IdentPos,'HIGH')=0) then
         begin
diff --git a/components/codetools/identcompletiontool.pas b/components/codetools/identcompletiontool.pas
index 42dd566397..5671b1c16a 100644
--- a/components/codetools/identcompletiontool.pas
+++ b/components/codetools/identcompletiontool.pas
@@ -1398,6 +1398,7 @@ begin
     AddCompilerProcedure('Finalize','var X');
     AddCompilerFunction('get_frame','','Pointer');
     AddCompilerFunction('High','Arg:TypeOrVariable','Ordinal');
+    AddCompilerFunction('IfThen','Condition:Boolean;ThenExpr,ElseExpr:T','T');
     AddCompilerProcedure('Inc','var X:Ordinal;N:Integer=1');
     AddCompilerProcedure('Include','var S:Set;X:Ordinal');
     AddCompilerProcedure('Initialize','var X');
@@ -2940,6 +2941,7 @@ var
       AddCompilerProc('Finalize','var X');
       AddCompilerProc('get_frame','','Pointer');
       AddCompilerProc('High','Arg:TypeOrVariable','Ordinal');
+      AddCompilerProc('IfThen','Condition:Boolean;ThenExpr,ElseExpr:T','T');
       AddCompilerProc('Inc','var X:Ordinal;N:Integer=1');
       AddCompilerProc('Include','var S:Set;X:Ordinal');
       AddCompilerProc('Initialize','var X');
diff --git a/components/codetools/keywordfunclists.pas b/components/codetools/keywordfunclists.pas
index 6fb64b9c2f..42ff87694e 100644
--- a/components/codetools/keywordfunclists.pas
+++ b/components/codetools/keywordfunclists.pas
@@ -1246,6 +1246,7 @@ begin
     Add('INC'         ,{$ifdef FPC}@{$endif}AllwaysTrue);
     Add('DEC'         ,{$ifdef FPC}@{$endif}AllwaysTrue);
     Add('DEFAULT'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
+    Add('IFTHEN'      ,{$ifdef FPC}@{$endif}AllwaysTrue);
     Add('INITIALIZE'  ,{$ifdef FPC}@{$endif}AllwaysTrue);
     Add('FINALIZE'    ,{$ifdef FPC}@{$endif}AllwaysTrue);
     Add('COPY'        ,{$ifdef FPC}@{$endif}AllwaysTrue);