diff --git a/include/ircd/asio.h b/include/ircd/asio.h
index b214ca9c0..af309d58d 100644
--- a/include/ircd/asio.h
+++ b/include/ircd/asio.h
@@ -27,8 +27,11 @@
 #define BOOST_COROUTINES_NO_DEPRECATION_WARNING
 #pragma GCC visibility push(default)
 
+// Boost preambles
 #include <boost/version.hpp>
+#include <boost/config.hpp>
 
+// Workarounds / fixes
 #if BOOST_VERSION >= 107000
 namespace boost
 {
@@ -37,7 +40,10 @@ namespace boost
 }
 #endif
 
-#include <boost/config.hpp>
+// Needed for consistent interop with std::system_error
+#include <boost/system/system_error.hpp>
+
+// Boost ASIO stack
 #include <boost/asio.hpp>
 #include <boost/asio/ssl.hpp>
 #include <boost/asio/steady_timer.hpp>
@@ -53,7 +59,10 @@ namespace boost
 /// need these low-level interfaces.
 ///
 
+// Context system headers depending on boost.
 #include <ircd/ctx/continuation.h>
+
+// Network system headers depending on boost.
 #include <ircd/net/asio.h>
 
 #endif HAVE_IRCD_ASIO_H
diff --git a/ircd/Makefile.am b/ircd/Makefile.am
index fd9dbe30d..6495835b2 100644
--- a/ircd/Makefile.am
+++ b/ircd/Makefile.am
@@ -187,6 +187,7 @@ db_write_thread.lo:   AM_CPPFLAGS += -I$(top_srcdir)/deps/rocksdb
 db_crc32.lo:          AM_CPPFLAGS := ${ROCKSDB_UNIT_CPPFLAGS} ${AM_CPPFLAGS}
 db_crc32.lo:          AM_CPPFLAGS += -I$(top_srcdir)/deps/rocksdb/include
 db_crc32.lo:          AM_CPPFLAGS += -I$(top_srcdir)/deps/rocksdb
+exception.lo:         AM_CPPFLAGS := ${ASIO_UNIT_CPPFLAGS} ${AM_CPPFLAGS}
 fmt.lo:               AM_CPPFLAGS := ${SPIRIT_UNIT_CPPFLAGS} ${AM_CPPFLAGS}
 fmt.lo:               AM_CXXFLAGS := ${SPIRIT_UNIT_CXXFLAGS} ${AM_CXXFLAGS}
 fs.lo:                AM_CPPFLAGS := ${ASIO_UNIT_CPPFLAGS} ${AM_CPPFLAGS}
diff --git a/ircd/exception.cc b/ircd/exception.cc
index 375502290..f1eae91bd 100644
--- a/ircd/exception.cc
+++ b/ircd/exception.cc
@@ -8,8 +8,6 @@
 // copyright notice and this permission notice is present in all copies. The
 // full license for this software is available in the LICENSE file.
 
-#include <boost/system/system_error.hpp>
-
 [[noreturn]] static void
 ircd_terminate_handler()
 noexcept