diff --git a/.gitattributes b/.gitattributes
index 6befbcf851..1262ed89c9 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -12774,6 +12774,7 @@ tests/webtbf/tw26176.pp svneol=native#text/pascal
 tests/webtbf/tw26193.pp svneol=native#text/pascal
 tests/webtbf/tw26363.pp svneol=native#text/plain
 tests/webtbf/tw26363a.pp svneol=native#text/plain
+tests/webtbf/tw26456.pp svneol=native#text/pascal
 tests/webtbf/tw2650.pp svneol=native#text/plain
 tests/webtbf/tw2657.pp svneol=native#text/plain
 tests/webtbf/tw2670.pp svneol=native#text/plain
diff --git a/compiler/symtable.pas b/compiler/symtable.pas
index 2538b03581..63705d6e65 100644
--- a/compiler/symtable.pas
+++ b/compiler/symtable.pas
@@ -2926,7 +2926,9 @@ implementation
               end;
           end;
         { now search in the extended type itself }
-        if classh.extendeddef.typ in [recorddef,objectdef] then
+        { Note: the extendeddef might be Nil if we are currently parsing the
+                extended type itself and the identifier was not found }
+        if assigned(classh.extendeddef) and (classh.extendeddef.typ in [recorddef,objectdef]) then
           begin
             srsymtable:=tabstractrecorddef(classh.extendeddef).symtable;
             srsym:=tsym(srsymtable.FindWithHash(hashedid));
diff --git a/tests/webtbf/tw26456.pp b/tests/webtbf/tw26456.pp
new file mode 100644
index 0000000000..fcc7abcea2
--- /dev/null
+++ b/tests/webtbf/tw26456.pp
@@ -0,0 +1,16 @@
+{ %FAIL }
+
+program tw26456;
+{$modeswitch advancedrecords}
+type
+  THelper = record helper for xxxxxxx
+    procedure test;
+  end;
+
+  procedure THelper.test;
+  begin
+  end;
+
+begin
+end.
+