diff --git a/.gitattributes b/.gitattributes
index 90094d6e30..6779241903 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -13512,6 +13512,7 @@ tests/webtbs/tw24865.pp svneol=native#text/pascal
 tests/webtbs/tw24871.pp svneol=native#text/pascal
 tests/webtbs/tw2492.pp svneol=native#text/plain
 tests/webtbs/tw2494.pp svneol=native#text/plain
+tests/webtbs/tw24953.pp svneol=native#text/pascal
 tests/webtbs/tw2503.pp svneol=native#text/plain
 tests/webtbs/tw2504.pp svneol=native#text/plain
 tests/webtbs/tw2514.pp svneol=native#text/plain
diff --git a/compiler/pgenutil.pas b/compiler/pgenutil.pas
index 225b2fedc8..af6f34ba94 100644
--- a/compiler/pgenutil.pas
+++ b/compiler/pgenutil.pas
@@ -1009,6 +1009,10 @@ uses
 
               for i:=firstidx to result.count-1 do
                 ttypesym(result[i]).typedef:=basedef;
+              { we need a typesym in case we do a Delphi-mode inline
+                specialization with this parameter; so just use the first sym }
+              if not assigned(basedef.typesym) then
+                basedef.typesym:=ttypesym(result[firstidx]);
               firstidx:=result.count;
 
               constraintdata.free;
diff --git a/tests/webtbs/tw24953.pp b/tests/webtbs/tw24953.pp
new file mode 100644
index 0000000000..ec9eaa49d7
--- /dev/null
+++ b/tests/webtbs/tw24953.pp
@@ -0,0 +1,24 @@
+unit tw24953;
+
+interface
+{$mode delphi}
+
+Type
+   TPoolablePool<t:class,constructor>   =   class
+                                        factory : TObject;
+                                        constructor create;
+                                      end;
+
+   TPoolableFactory<t>= class
+   end;
+
+implementation
+
+{ TPoolablePool<t> }
+
+constructor TPoolablePool<t>.create;  // last line visible in -va output before crash
+begin
+  factory:=TPoolableFactory<t>.create;
+end;
+
+end.