diff --git a/src/vim9expr.c b/src/vim9expr.c
index 120a606..a158f31 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -367,12 +367,19 @@
 	}
 	if (ufunc == NULL)
 	{
-	    // TODO: different error for object method?
-	    semsg(_(e_method_not_found_on_class_str_str), cl->class_name, name);
+	    method_not_found_msg(cl, type->tt_type, name, len);
 	    return FAIL;
 	}
 
-	if (*ufunc->uf_name == '_' && !inside_class_hierarchy(cctx, cl))
+	// A private object method can be used only inside the class where it
+	// is defined or in one of the child classes.
+	// A private class method can be used only in the class where it is
+	// defined.
+	if (*ufunc->uf_name == '_' &&
+		((type->tt_type == VAR_OBJECT
+		  && !inside_class_hierarchy(cctx, cl))
+		 || (type->tt_type == VAR_CLASS
+		     && cctx->ctx_ufunc->uf_class != cl)))
 	{
 	    semsg(_(e_cannot_access_private_method_str), name);
 	    return FAIL;
@@ -422,7 +429,7 @@
 	    return generate_FUNCREF(cctx, fp, NULL, 0, NULL);
 	}
 
-	semsg(_(e_member_not_found_on_object_str_str), cl->class_name, name);
+	member_not_found_msg(cl, VAR_OBJECT, name, len);
     }
     else
     {
@@ -438,7 +445,9 @@
 			cl->class_name, m->ocm_name);
 		return FAIL;
 	    }
-	    if (*name == '_' && !inside_class(cctx, cl))
+	    // A private class variable can be accessed only in the class where
+	    // it is defined.
+	    if (*name == '_' && cctx->ctx_ufunc->uf_class != cl)
 	    {
 		semsg(_(e_cannot_access_private_member_str), m->ocm_name);
 		return FAIL;
@@ -447,7 +456,7 @@
 	    *arg = name_end;
 	    return generate_CLASSMEMBER(cctx, TRUE, cl, idx);
 	}
-	semsg(_(e_class_member_not_found_str), name);
+	member_not_found_msg(cl, VAR_CLASS, name, len);
     }
 
     return FAIL;
@@ -762,9 +771,17 @@
 	    }
 	    else if ((idx = cctx_class_member_idx(cctx, *arg, len, &cl)) >= 0)
 	    {
-		// Referencing a class member without the class name.  Infer
-		// the class from the def function context.
-		res = generate_CLASSMEMBER(cctx, TRUE, cl, idx);
+		// Referencing a class variable without the class name.
+		// A class variable can be referenced without the class name
+		// only in the class where the function is defined.
+		if (cctx->ctx_ufunc->uf_defclass == cl)
+		    res = generate_CLASSMEMBER(cctx, TRUE, cl, idx);
+		else
+		{
+		    semsg(_(e_class_member_str_accessible_only_inside_class_str),
+			    name, cl->class_name);
+		    res = FAIL;
+		}
 	    }
 	    else
 	    {
@@ -1130,12 +1147,23 @@
 	}
 	else if ((mi = cctx_class_method_idx(cctx, name, varlen, &cl)) >= 0)
 	{
-	    // Class method invocation without the class name.  The
-	    // generate_CALL() function expects the class type at the top of
-	    // the stack.  So push the class type to the stack.
-	    push_type_stack(cctx, &t_class);
-	    res = generate_CALL(cctx, cl->class_class_functions[mi], NULL, 0,
-							type, argcount);
+	    // Class method invocation without the class name.
+	    // A class method can be referenced without the class name only in
+	    // the class where the function is defined.
+	    if (cctx->ctx_ufunc->uf_defclass == cl)
+	    {
+		// The generate_CALL() function expects the class type at the
+		// top of the stack.  So push the class type to the stack.
+		push_type_stack(cctx, &t_class);
+		res = generate_CALL(cctx, cl->class_class_functions[mi], NULL,
+							0, type, argcount);
+	    }
+	    else
+	    {
+		semsg(_(e_class_member_str_accessible_only_inside_class_str),
+			name, cl->class_name);
+		res = FAIL;
+	    }
 	    goto theend;
 	}
     }