diff --git a/xo-arena/include/xo/arena/AllocHeader.hpp b/xo-arena/include/xo/arena/AllocHeader.hpp
index ec99f599..db8b6785 100644
--- a/xo-arena/include/xo/arena/AllocHeader.hpp
+++ b/xo-arena/include/xo/arena/AllocHeader.hpp
@@ -11,6 +11,13 @@
 
 namespace xo {
     namespace mm {
+        /** @brief per-alloc header
+         *
+         *  Appears immediately before each allocation when
+         *  ArenaConfig.store_header_flag_ is set.
+         *
+         *  See AllocInfo.hpp for encoding of @ref repr_
+         **/
         struct AllocHeader {
             using repr_type = std::uintptr_t;
             using size_type = std::size_t;
diff --git a/xo-reader2/include/xo/reader2/ParserConfig.hpp b/xo-reader2/include/xo/reader2/ParserConfig.hpp
index ce781b16..080238c7 100644
--- a/xo-reader2/include/xo/reader2/ParserConfig.hpp
+++ b/xo-reader2/include/xo/reader2/ParserConfig.hpp
@@ -20,7 +20,7 @@ namespace xo {
             ArenaConfig parser_arena_config_ { .name_ = "parser-arena",
                                                .size_ = 2*1024*1024,
                                                .hugepage_z_ = 2*1024*1024,
-                                               .store_header_flag_ = false,
+                                               .store_header_flag_ = true,
                                                .header_{},
                                                .debug_flag_ = false };
 
diff --git a/xo-reader2/src/reader2/reader2_register_facets.cpp b/xo-reader2/src/reader2/reader2_register_facets.cpp
index 7a653954..845b8d8e 100644
--- a/xo-reader2/src/reader2/reader2_register_facets.cpp
+++ b/xo-reader2/src/reader2/reader2_register_facets.cpp
@@ -77,6 +77,8 @@ namespace xo {
 
             // misc types showing up in aux arena
             TypeRegistry::register_type<SchematikaParser>();
+            // misc types showing up in parser stack arena
+            TypeRegistry::register_type<ParserStack>();
 
             log && log(xtag("DExprSeqState.tseq", typeseq::id<DExprSeqState>()));
             log && log(xtag("DDefineSsm.tseq", typeseq::id<DDefineSsm>()));
diff --git a/xo-reader2/utest/SchematikaParser.test.cpp b/xo-reader2/utest/SchematikaParser.test.cpp
index 5d831b13..a0557fa6 100644
--- a/xo-reader2/utest/SchematikaParser.test.cpp
+++ b/xo-reader2/utest/SchematikaParser.test.cpp
@@ -194,7 +194,7 @@ namespace xo {
         {
             const auto & testname = Catch::getResultCapture().getCurrentTestName();
 
-            constexpr bool c_debug_flag = true;
+            constexpr bool c_debug_flag = false;
             scope log(XO_DEBUG(c_debug_flag), xtag("test", testname));
 
             ParserFixture fixture(testname, c_debug_flag);
@@ -740,7 +740,7 @@ namespace xo {
 
             const auto & testname = Catch::getResultCapture().getCurrentTestName();
 
-            constexpr bool c_debug_flag = false;
+            constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag), xtag("test", testname));
 
             ParserFixture fixture(testname, c_debug_flag);