diff --git a/ircd/json.cc b/ircd/json.cc
index 263ca5228..2e23e8967 100644
--- a/ircd/json.cc
+++ b/ircd/json.cc
@@ -210,6 +210,16 @@ ircd::json::printer
 :karma::grammar<char *, unused_type>
 {
 	using it = char *;
+	using prop_mask = mpl_::int_
+	<
+		karma::generator_properties::no_properties
+		| karma::generator_properties::buffering
+		| karma::generator_properties::counting
+		| karma::generator_properties::tracking
+		| karma::generator_properties::disabling
+	>;
+	using sink_type = karma::detail::output_iterator<it, prop_mask, unused_type>;
+	static thread_local mutable_buffer *sink_buffer;
 
 	template<class T = unused_type,
 	         class... A>
@@ -454,6 +464,43 @@ noexcept
 	}
 }
 
+thread_local
+decltype(ircd::json::printer::sink_buffer)
+ircd::json::printer::sink_buffer;
+
+template<>
+[[gnu::visibility("internal")]]
+inline bool
+boost::spirit::karma::detail::buffer_sink::copy(ircd::json::printer::sink_type &sink,
+                                                size_t maxwidth)
+const
+{
+	assert(ircd::json::printer::sink_buffer);
+	return true;
+}
+
+template<>
+[[gnu::visibility("internal")]]
+inline bool
+boost::spirit::karma::detail::buffer_sink::copy_rest(ircd::json::printer::sink_type &sink,
+                                                     size_t start_at)
+const
+{
+	assert(ircd::json::printer::sink_buffer);
+	assert(false);
+	return true;
+}
+
+template<>
+[[gnu::visibility("internal")]]
+inline void
+boost::spirit::karma::detail::buffer_sink::output(const char &value)
+{
+	assert(ircd::json::printer::sink_buffer);
+	auto &buf(*ircd::json::printer::sink_buffer);
+	ircd::consume(buf, ircd::copy(buf, value));
+}
+
 template<class gen,
          class... attr>
 [[gnu::visibility("internal")]]
@@ -463,16 +510,6 @@ ircd::json::printer::operator()(mutable_buffer &out,
                                 attr&&... a)
 const
 {
-	const auto maxwidth
-	{
-		karma::maxwidth(size(out))
-	};
-
-	const auto gg
-	{
-		maxwidth[std::forward<gen>(g)]
-	};
-
 	const auto throws{[&out]
 	{
 		throw print_panic
@@ -484,9 +521,30 @@ const
 		};
 	}};
 
+	const auto maxwidth
+	{
+		karma::maxwidth(size(out))
+	};
+
+	const auto gg
+	{
+		maxwidth[std::forward<gen>(g)]
+	};
+
+	assert(!sink_buffer);
+	const scope_restore set_sink_buffer
+	{
+		sink_buffer, &out
+	};
+
+	sink_type sink
+	{
+		begin(out)
+	};
+
 	const auto ret
 	{
-		karma::generate(begin(out), gg | eps[throws], std::forward<attr>(a)...)
+		karma::generate(sink, gg | eps[throws], std::forward<attr>(a)...)
 	};
 
 	return ret;
@@ -499,16 +557,6 @@ ircd::json::printer::operator()(mutable_buffer &out,
                                 gen&& g)
 const
 {
-	const auto maxwidth
-	{
-		karma::maxwidth(size(out))
-	};
-
-	const auto gg
-	{
-		maxwidth[std::forward<gen>(g)]
-	};
-
 	const auto throws{[&out]
 	{
 		throw print_panic
@@ -519,9 +567,30 @@ const
 		};
 	}};
 
+	const auto maxwidth
+	{
+		karma::maxwidth(size(out))
+	};
+
+	const auto gg
+	{
+		maxwidth[std::forward<gen>(g)]
+	};
+
+	assert(!sink_buffer);
+	const scope_restore set_sink_buffer
+	{
+		sink_buffer, &out
+	};
+
+	sink_type sink
+	{
+		begin(out)
+	};
+
 	const auto ret
 	{
-		karma::generate(begin(out), gg | eps[throws])
+		karma::generate(sink, gg | eps[throws])
 	};
 
 	return ret;