diff --git a/adapter.hpp b/adapter.hpp
index a585e222..190968cc 100644
--- a/adapter.hpp
+++ b/adapter.hpp
@@ -6,9 +6,9 @@
  * Copyright 2015-2019 Danny Robson <danny@nerdcruft.net>
  */
 
-#include <array>
 #include <cstddef>
 #include <iterator>
+#include <tuple>
 
 
 namespace cruft::adapter {
diff --git a/cmdopt.hpp b/cmdopt.hpp
index ca750958..94141d88 100644
--- a/cmdopt.hpp
+++ b/cmdopt.hpp
@@ -6,7 +6,6 @@
  * Copyright 2013-2016 Danny Robson <danny@nerdcruft.net>
  */
 
-
 #ifndef CRUFT_UTIL_CMDLINE_HPP
 #define CRUFT_UTIL_CMDLINE_HPP
 
@@ -17,7 +16,6 @@
 #include <functional>
 #include <memory>
 #include <string>
-#include <tuple>
 #include <vector>
 #include <map>
 #include <sstream>
diff --git a/colour.hpp b/colour.hpp
index de87be52..54ba96f2 100644
--- a/colour.hpp
+++ b/colour.hpp
@@ -10,9 +10,7 @@
 #define __UTIL_COLOUR_HPP
 
 #include "coord.hpp"
-#include "introspection.hpp"
 
-#include <ostream>
 #include <type_traits>
 
 
diff --git a/cpp.cpp b/cpp.cpp
index 746ce02f..d520e782 100644
--- a/cpp.cpp
+++ b/cpp.cpp
@@ -11,7 +11,6 @@
 #include "cpp.hpp"
 
 #include "io.hpp"
-#include "cast.hpp"
 
 using cruft::cpp::include;
 using cruft::cpp::passthrough;
diff --git a/encode/base.hpp b/encode/base.hpp
index a83b8b46..ad8627a5 100644
--- a/encode/base.hpp
+++ b/encode/base.hpp
@@ -12,7 +12,6 @@
 #include "../view.hpp"
 
 #include <cstdint>
-#include <array>
 
 
 namespace cruft::encode {
diff --git a/endian.hpp b/endian.hpp
index 5a142862..2b5adcaa 100644
--- a/endian.hpp
+++ b/endian.hpp
@@ -10,14 +10,13 @@
 
 #include "std.hpp"
 #include "types/bits.hpp"
-#include "cast.hpp"
 
-#include <compare>
 #include <cstdint>
 #include <cstring>
 #include <iosfwd>
 #include <type_traits>
 
+
 namespace cruft {
     //-------------------------------------------------------------------------
     // CXX: Update using "if constexpr" when available. It doesn't seem to be
diff --git a/fixed.hpp b/fixed.hpp
index 6b43da64..8f257a8a 100644
--- a/fixed.hpp
+++ b/fixed.hpp
@@ -11,7 +11,6 @@
 
 #include "types/bits.hpp"
 #include "maths.hpp"
-#include "endian.hpp"
 
 #include <iosfwd>
 
diff --git a/geom/aabb.hpp b/geom/aabb.hpp
index 40671808..a412fbf6 100644
--- a/geom/aabb.hpp
+++ b/geom/aabb.hpp
@@ -12,8 +12,6 @@
 #include "../extent.hpp"
 #include "../point.hpp"
 
-#include <cstdint>
-
 
 namespace cruft::geom {
     ///////////////////////////////////////////////////////////////////////////
diff --git a/geom/plane.hpp b/geom/plane.hpp
index a9918aaa..bc11671b 100644
--- a/geom/plane.hpp
+++ b/geom/plane.hpp
@@ -10,7 +10,7 @@
 
 #include "../point.hpp"
 #include "../vector.hpp"
-#include "../matrix.hpp"
+
 
 namespace cruft::geom {
     /// represents an S dimensional plane in parametric form: ax + by + cz + d = 0
diff --git a/geom/ray.hpp b/geom/ray.hpp
index 4dfc3ddf..84e4ad2d 100644
--- a/geom/ray.hpp
+++ b/geom/ray.hpp
@@ -6,13 +6,13 @@
  * Copyright 2015-2018 Danny Robson <danny@nerdcruft.net>
  */
 
-#ifndef __UTIL_GEOM_RAY_HPP
-#define __UTIL_GEOM_RAY_HPP
+#pragma once
 
 #include "aabb.hpp"
 #include "plane.hpp"
 #include "../vector.hpp"
 #include "../point.hpp"
+#include "../matrix.hpp"
 
 #include <iosfwd>
 
@@ -134,5 +134,3 @@ namespace cruft::geom {
     std::ostream&
     operator<< (std::ostream&, ray<S,T>);
 }
-
-#endif
diff --git a/introspection.hpp b/introspection.hpp
index ec0c922e..58ba4739 100644
--- a/introspection.hpp
+++ b/introspection.hpp
@@ -9,7 +9,6 @@
 #pragma once
 
 #include "std.hpp"
-#include "variadic.hpp"
 #include "algo/search.hpp"
 
 #include <cruft/util/preprocessor.hpp>
@@ -18,7 +17,6 @@
 #include <array>
 #include <cstddef>
 #include <cstdint>
-#include <filesystem>
 #include <ostream>
 #include <string>
 #include <string_view>
diff --git a/job/queue.hpp b/job/queue.hpp
index 1bc65645..97aeb00b 100644
--- a/job/queue.hpp
+++ b/job/queue.hpp
@@ -19,15 +19,12 @@
 
 #include "../parallel/queue.hpp"
 
-#include <array>
-#include <deque>
-#include <vector>
-#include <new>
-#include <cstddef>
-#include <functional>
 #include <atomic>
-#include <mutex>
-#include <condition_variable>
+#include <cstddef>
+#include <deque>
+#include <functional>
+#include <new>
+#include <vector>
 
 
 namespace cruft::job {
diff --git a/log/sink/path.hpp b/log/sink/path.hpp
index 41e8b42b..f69efc59 100644
--- a/log/sink/path.hpp
+++ b/log/sink/path.hpp
@@ -12,7 +12,6 @@
 
 #include <string>
 #include <fstream>
-#include <filesystem>
 
 
 namespace cruft::log::sink {
diff --git a/map/fixed.hpp b/map/fixed.hpp
index 413ed2fc..f15fcbd1 100644
--- a/map/fixed.hpp
+++ b/map/fixed.hpp
@@ -10,7 +10,6 @@
 
 #include "../debug/assert.hpp"
 
-#include <array>
 #include <utility>
 #include <stdexcept>
 #include <functional>
diff --git a/point.hpp b/point.hpp
index 397e744d..ac3f7fae 100644
--- a/point.hpp
+++ b/point.hpp
@@ -14,9 +14,9 @@
 #include "maths.hpp"
 #include "view.hpp"
 
-#include <algorithm>
 #include <type_traits>
 
+
 namespace cruft {
     /// An n-dimensional position in space.
     ///
diff --git a/signal.hpp b/signal.hpp
index 40fdaf01..7dbe49c7 100644
--- a/signal.hpp
+++ b/signal.hpp
@@ -11,10 +11,10 @@
 #include "types/traits.hpp"
 #include "debug/assert.hpp"
 
-#include <algorithm>
 #include <functional>
 #include <list>
 
+
 namespace cruft {
     namespace reduce {
         /// Returns the short-circuited logical-and of the results of all
diff --git a/stream.hpp b/stream.hpp
index 21fd598a..e07d9450 100644
--- a/stream.hpp
+++ b/stream.hpp
@@ -10,8 +10,9 @@
 #define __UTIL_STREAM_HPP
 
 #include <iosfwd>
-#include <iomanip>
 #include <cstdint>
+#include <ostream>
+
 
 namespace cruft::stream {
     namespace scoped {
diff --git a/strongdef.hpp b/strongdef.hpp
index 81f4e94d..cc02511c 100644
--- a/strongdef.hpp
+++ b/strongdef.hpp
@@ -11,7 +11,6 @@
 #include "cast.hpp"
 #include "types/traits.hpp"
 
-#include <limits>
 #include <type_traits>
 #include <iosfwd>
 
diff --git a/typeidx.hpp b/typeidx.hpp
index f288cba4..d2589062 100644
--- a/typeidx.hpp
+++ b/typeidx.hpp
@@ -10,7 +10,6 @@
 
 #include <atomic>
 
-#include <cstdint>
 
 namespace cruft {
     namespace detail {