diff --git a/.gitattributes b/.gitattributes
index cdd34ab9c4..2a2b47464a 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -16076,6 +16076,7 @@ tests/webtbs/tw3328a.pp svneol=native#text/plain
 tests/webtbs/tw3328b.pp svneol=native#text/plain
 tests/webtbs/tw3334.pp svneol=native#text/plain
 tests/webtbs/tw3340.pp svneol=native#text/plain
+tests/webtbs/tw33414.pp svneol=native#text/pascal
 tests/webtbs/tw33417.pp svneol=native#text/pascal
 tests/webtbs/tw3348.pp svneol=native#text/plain
 tests/webtbs/tw3349.pp svneol=native#text/plain
diff --git a/compiler/ptype.pas b/compiler/ptype.pas
index 6e5aca5450..fdd3162eb1 100644
--- a/compiler/ptype.pas
+++ b/compiler/ptype.pas
@@ -1322,6 +1322,13 @@ implementation
                   else
                     Message1(parser_e_type_cant_be_used_in_array_index,def.typename);
                 end;
+              { generic parameter? }
+              undefineddef:
+                begin
+                  lowval:=0;
+                  highval:=1;
+                  indexdef:=def;
+                end;
               else
                 Message(sym_e_error_in_type_def);
             end;
diff --git a/tests/webtbs/tw33414.pp b/tests/webtbs/tw33414.pp
new file mode 100644
index 0000000000..766944671b
--- /dev/null
+++ b/tests/webtbs/tw33414.pp
@@ -0,0 +1,20 @@
+{$mode objfpc}{$H+}
+uses Classes, SysUtils;
+
+type
+  generic TFoo<SomeEnum> = class
+    m: array[SomeEnum] of integer;
+  end;
+
+  TEnum = (e0, e1);
+
+var
+  a: specialize TFoo<TEnum>;
+
+begin
+  if low(a.m)<>e0 then
+    halt(1);
+  if high(a.m)<>e1 then
+    halt(1);
+  writeln('ok');
+end.