diff --git a/src/Type.cc b/src/Type.cc
index 0baff8b2ee..30ff3ce897 100644
--- a/src/Type.cc
+++ b/src/Type.cc
@@ -30,6 +30,7 @@ const char* type_name(TypeTag t)
 		"table", "union", "record", "types",
 		"func",
 		"file",
+		"opaque",
 		"vector",
 		"type",
 		"error",