diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_xhtml_format.c b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_xhtml_format.c
index 192288aff1bc2d02c6b94511bcd71bb8b7762a9f..0f13e8d6d01a7a44ba4044de218cc4b4652d97af 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_xhtml_format.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_xhtml_format.c
@@ -751,7 +751,7 @@ diagnostic_output_format_init_xhtml_file (diagnostic_context &context,
 namespace selftest {
 
 /* A subclass of xhtml_output_format for writing selftests.
-   The JSON output is cached internally, rather than written
+   The XML output is cached internally, rather than written
    out to a file.  */
 
 class test_xhtml_diagnostic_context : public test_diagnostic_context