diff --git a/TestSuite/CompilationSamples/PABCSystem.pas b/TestSuite/CompilationSamples/PABCSystem.pas
index 009cc26e3..29428fb81 100644
--- a/TestSuite/CompilationSamples/PABCSystem.pas
+++ b/TestSuite/CompilationSamples/PABCSystem.pas
@@ -8212,7 +8212,7 @@ function LogN(base, x: real) := Math.Log(x) / Math.Log(base);
 
 function Sqrt(x: real) := Math.Sqrt(x);
 
-function Sqr(x: integer): int64 := x * x;
+function Sqr(x: integer): int64 := int64(x) * int64(x);
 
 function Sqr(x: shortint): integer := x * x;
 
@@ -8222,11 +8222,11 @@ function Sqr(x: BigInteger): BigInteger := x * x;
 
 function Sqr(x: byte): integer := x * x;
 
-function Sqr(x: word): uint64 := x * x;
+function Sqr(x: word): uint64 := uint64(x) * uint64(x);
 
-function Sqr(x: longword): uint64 := x * x;
+function Sqr(x: longword): uint64 := uint64(x) * uint64(x);
 
-function Sqr(x: int64): int64 := x * x;
+function Sqr(x: int64): int64 := int64(x) * int64(x);
 
 function Sqr(x: uint64): uint64 := x * x;
 
diff --git a/TestSuite/lambdas_generics10.pas b/TestSuite/lambdas_generics10.pas
new file mode 100644
index 000000000..6eefca952
--- /dev/null
+++ b/TestSuite/lambdas_generics10.pas
@@ -0,0 +1,26 @@
+type
+  
+  t0<T> = class
+  where T: t0<T>;
+    b: boolean;
+    
+    static procedure p1(a: T);
+    begin
+      var f: Func<T, boolean> := o -> o.b;
+      assert(f(a));
+    end;
+    
+    static procedure p2(a: T);
+    begin
+      assert(a.b);
+    end;
+  end;
+  
+  t1 = class(t0<t1>) end;
+  
+begin
+  var a := new t1;
+  a.b := true;
+  t1.p1(a);
+  t1.p2(a);
+end.
\ No newline at end of file
diff --git a/TreeConverter/TreeConversion/syntax_tree_visitor.cs b/TreeConverter/TreeConversion/syntax_tree_visitor.cs
index fb08ac26d..77383ff7c 100644
--- a/TreeConverter/TreeConversion/syntax_tree_visitor.cs
+++ b/TreeConverter/TreeConversion/syntax_tree_visitor.cs
@@ -11974,6 +11974,8 @@ namespace PascalABCCompiler.TreeConverter
             {
                 make_attributes_for_declaration(_type_declaration, ctn);
             }
+            if (cl_def.keyword == class_keyword.Class || cl_def.keyword == class_keyword.Interface)
+                ctn.is_class = true;//nado ranshe pomechat kak is_class
             if (is_generic)
             {
                 if (predefined_generic)
@@ -12011,6 +12013,7 @@ namespace PascalABCCompiler.TreeConverter
                         AddError(get_location(cl_def.class_parents.types[i]), "PARTIAL_CLASS_PARENTS_MISMATCH");
                 }*/
             }
+            
             visit_where_list(cl_def.where_section);
            
             CheckWaitedRefTypes(ctn);