diff --git a/.gitattributes b/.gitattributes
index 6bd8dcaae2..5405511ce0 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -8135,6 +8135,7 @@ tests/webtbs/tw1104.pp svneol=native#text/plain
 tests/webtbs/tw11042.pp svneol=native#text/plain
 tests/webtbs/tw11053.pp svneol=native#text/plain
 tests/webtbs/tw1111.pp svneol=native#text/plain
+tests/webtbs/tw11139.pp svneol=native#text/plain
 tests/webtbs/tw1117.pp svneol=native#text/plain
 tests/webtbs/tw1122.pp svneol=native#text/plain
 tests/webtbs/tw1123.pp svneol=native#text/plain
diff --git a/compiler/htypechk.pas b/compiler/htypechk.pas
index 0df200c3ba..780b3a09c2 100644
--- a/compiler/htypechk.pas
+++ b/compiler/htypechk.pas
@@ -2364,8 +2364,20 @@ implementation
                   ord(currvcl in conflictvcls)-ord(bestvcl in conflictvcls);
         end;
 
+
+        function getfirstrealparaidx(pd: pcandidate): integer;
+          begin
+            { can be different for currpd and bestpd in case of overloaded }
+            { functions, e.g. lowercase():char and lowercase():shortstring }
+            { (depending on the calling convention and parameter order)    }
+            result:=pd^.firstparaidx;
+            while (result>=0) and (vo_is_hidden_para in tparavarsym(pd^.data.paras[result]).varoptions) do
+              dec(result);
+            if (vo_is_hidden_para in tparavarsym(pd^.data.paras[result]).varoptions) then
+              internalerror(2006122803);
+          end;
+
       var
-        paraidx : integer;
         currpara, bestpara: tparavarsym;
         currvcl, bestvcl: tvariantequaltype;
       begin
@@ -2375,18 +2387,8 @@ implementation
             < 0 when bestpd is better than currpd
             = 0 when both are equal
         }
-        if (currpd^.firstparaidx<>bestpd^.firstparaidx) then
-          internalerror(2006122801);
-         paraidx:=currpd^.firstparaidx;
-         while (paraidx>=0) and (vo_is_hidden_para in tparavarsym(currpd^.data.paras[paraidx]).varoptions) do
-           if (vo_is_hidden_para in tparavarsym(bestpd^.data.paras[paraidx]).varoptions) then
-             dec(paraidx)
-           else
-             internalerror(2006122802);
-        if (vo_is_hidden_para in tparavarsym(currpd^.data.paras[paraidx]).varoptions) then
-          internalerror(2006122803);
-        currpara:=tparavarsym(currpd^.data.paras[paraidx]);
-        bestpara:=tparavarsym(bestpd^.data.paras[paraidx]);
+        currpara:=tparavarsym(currpd^.data.paras[getfirstrealparaidx(currpd)]);
+        bestpara:=tparavarsym(bestpd^.data.paras[getfirstrealparaidx(bestpd)]);
 
         { if one of the parameters is a regular variant, fall back to the }
         { default algorithm                                               }
diff --git a/tests/webtbs/tw11139.pp b/tests/webtbs/tw11139.pp
new file mode 100644
index 0000000000..903ee5e7f3
--- /dev/null
+++ b/tests/webtbs/tw11139.pp
@@ -0,0 +1,28 @@
+function f(c: char): char; overload;
+begin
+  halt(1);
+end;
+
+function f(const s: shortstring): shortstring; overload;
+begin
+  f:=lowercase(s);
+end;
+
+function f(const a: ansistring): ansistring; overload;
+begin
+  halt(3);
+end;
+
+Procedure DoIt;
+var avar:variant;
+      txt:String;
+Begin
+avar:='Hello';
+txt:=f(avar);//this line causes the compilation error
+if (txt<>'hello') then
+  halt(4);
+end;
+
+begin
+  doit;
+end.