diff --git a/compiler/cpp/src/generate/t_html_generator.cc b/compiler/cpp/src/generate/t_html_generator.cc
index 6372ab4..3633e62 100644
--- a/compiler/cpp/src/generate/t_html_generator.cc
+++ b/compiler/cpp/src/generate/t_html_generator.cc
@@ -579,6 +579,8 @@
   f_out_ << "<h3 id=\"Struct_" << name << "\">";
   if (tstruct->is_xception()) {
     f_out_ << "Exception: ";
+  } else if (tstruct->is_union()) {
+    f_out_ << "Union: ";
   } else {
     f_out_ << "Struct: ";
   }