diff --git a/tests/headers/derive-debug-bitfield.hpp b/tests/headers/derive-debug-bitfield.hpp
index 4d8c377113..6e31b66f6b 100644
--- a/tests/headers/derive-debug-bitfield.hpp
+++ b/tests/headers/derive-debug-bitfield.hpp
@@ -1,4 +1,4 @@
-// bindgen-flags: --opaque-type "Opaque" --force-derive-debug
+// bindgen-flags: --force-derive-debug
 
 class C {
   bool a: 1;
diff --git a/tests/headers/derive-debug-opaque-template-instantiation.hpp b/tests/headers/derive-debug-opaque-template-instantiation.hpp
index 555ba82613..d418e66920 100644
--- a/tests/headers/derive-debug-opaque-template-instantiation.hpp
+++ b/tests/headers/derive-debug-opaque-template-instantiation.hpp
@@ -1,5 +1,7 @@
 // bindgen-flags: --force-derive-debug
 
+// This type is opaque because the second template parameter
+// is a non-type template parameter
 template<typename T, int N>
 class Opaque {
   T array[N];