diff --git a/i3-config-wizard/main.c b/i3-config-wizard/main.c
index e857f1b4..9e07d1f7 100644
--- a/i3-config-wizard/main.c
+++ b/i3-config-wizard/main.c
@@ -9,7 +9,6 @@
  *
  */
 #include <config.h>
-#include "libi3.h"
 
 #include "libi3.h"
 
diff --git a/i3-nagbar/main.c b/i3-nagbar/main.c
index be29aa0f..51e5475c 100644
--- a/i3-nagbar/main.c
+++ b/i3-nagbar/main.c
@@ -9,6 +9,7 @@
  *
  */
 #include <config.h>
+
 #include "libi3.h"
 
 #include <err.h>
diff --git a/include/all.h b/include/all.h
index aa2b5b25..55111944 100644
--- a/include/all.h
+++ b/include/all.h
@@ -15,31 +15,24 @@
 #include <config.h>
 
 #include <assert.h>
+#include <err.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdarg.h>
 #include <stdbool.h>
-#include <stdlib.h>
+#include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
-#include <locale.h>
-#include <getopt.h>
-#include <unistd.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <glob.h>
-#include <errno.h>
-#include <err.h>
-#include <stdint.h>
-#include <inttypes.h>
-#include <math.h>
-#include <limits.h>
 
 #include <xcb/xcb.h>
 #include <xcb/xcb_aux.h>
-#include <xcb/xcb_keysyms.h>
 #include <xcb/xcb_icccm.h>
+#include <xcb/xcb_keysyms.h>
 
-#include <yajl/yajl_gen.h>
-#include <yajl/yajl_version.h>
-
+#include "libi3.h"
 #include "data.h"
 #include "util.h"
 #include "ipc.h"
@@ -72,7 +65,6 @@
 #include "ewmh.h"
 #include "assignments.h"
 #include "regex.h"
-#include "libi3.h"
 #include "startup.h"
 #include "scratchpad.h"
 #include "commands.h"
diff --git a/include/configuration.h b/include/configuration.h
index d7c2ab8b..eae36057 100644
--- a/include/configuration.h
+++ b/include/configuration.h
@@ -12,9 +12,6 @@
  */
 #pragma once
 
-#include "libi3.h"
-
-#include <stdbool.h>
 #include "queue.h"
 #include "i3.h"
 
diff --git a/include/data.h b/include/data.h
index e686d2c7..494dbe0a 100644
--- a/include/data.h
+++ b/include/data.h
@@ -9,13 +9,10 @@
  */
 #pragma once
 
-#include "libi3.h"
-
 #define SN_API_NOT_YET_FROZEN 1
 #include <libsn/sn-launcher.h>
 
 #include <xcb/randr.h>
-#include <stdbool.h>
 #include <pcre.h>
 #include <sys/time.h>
 
diff --git a/include/ipc.h b/include/ipc.h
index 8ea9fd2e..bc5929ec 100644
--- a/include/ipc.h
+++ b/include/ipc.h
@@ -12,7 +12,6 @@
 #include <config.h>
 
 #include <ev.h>
-#include <stdbool.h>
 #include <yajl/yajl_gen.h>
 #include <yajl/yajl_parse.h>
 
diff --git a/include/log.h b/include/log.h
index 5c530231..d3c3e3f3 100644
--- a/include/log.h
+++ b/include/log.h
@@ -11,9 +11,6 @@
 
 #include <config.h>
 
-#include <stdarg.h>
-#include <stdbool.h>
-
 /* We will include libi3.h which define its own version of LOG, ELOG.
  * We want *our* version, so we undef the libi3 one. */
 #if defined(LOG)
diff --git a/include/shmlog.h b/include/shmlog.h
index dc8081f1..7b7e133a 100644
--- a/include/shmlog.h
+++ b/include/shmlog.h
@@ -12,7 +12,6 @@
 
 #include <config.h>
 
-#include <stdint.h>
 #if !defined(__OpenBSD__)
 #include <pthread.h>
 #endif
diff --git a/include/xinerama.h b/include/xinerama.h
index f01ee568..52a5db33 100644
--- a/include/xinerama.h
+++ b/include/xinerama.h
@@ -13,8 +13,6 @@
 
 #include <config.h>
 
-#include "data.h"
-
 /**
  * We have just established a connection to the X server and need the initial
  * Xinerama information to setup workspaces for each screen.
diff --git a/src/bindings.c b/src/bindings.c
index 74d70c5c..e29f2c2d 100644
--- a/src/bindings.c
+++ b/src/bindings.c
@@ -8,6 +8,8 @@
  */
 #include "all.h"
 
+#include <math.h>
+
 #include <xkbcommon/xkbcommon-x11.h>
 #include <xkbcommon/xkbcommon.h>
 
diff --git a/src/display_version.c b/src/display_version.c
index 0185d1ed..32250c15 100644
--- a/src/display_version.c
+++ b/src/display_version.c
@@ -12,6 +12,7 @@
 
 #include <fcntl.h>
 #include <time.h>
+#include <unistd.h>
 
 static bool human_readable_key, loaded_config_file_name_key;
 static char *human_readable_version, *loaded_config_file_name;
diff --git a/src/floating.c b/src/floating.c
index 4fed43e4..5e60aa82 100644
--- a/src/floating.c
+++ b/src/floating.c
@@ -9,6 +9,8 @@
  */
 #include "all.h"
 
+#include <math.h>
+
 #ifndef MAX
 #define MAX(x, y) ((x) > (y) ? (x) : (y))
 #endif
diff --git a/src/ipc.c b/src/ipc.c
index 7e62b102..e616a53e 100644
--- a/src/ipc.c
+++ b/src/ipc.c
@@ -14,9 +14,11 @@
 #include <ev.h>
 #include <fcntl.h>
 #include <libgen.h>
+#include <locale.h>
 #include <stdint.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <unistd.h>
 
 #include <yajl/yajl_gen.h>
 #include <yajl/yajl_parse.h>
diff --git a/src/load_layout.c b/src/load_layout.c
index ccf965da..c0be3f26 100644
--- a/src/load_layout.c
+++ b/src/load_layout.c
@@ -10,6 +10,8 @@
  */
 #include "all.h"
 
+#include <locale.h>
+
 #include <yajl/yajl_parse.h>
 
 /* TODO: refactor the whole parsing thing */
diff --git a/src/log.c b/src/log.c
index 73093da1..326f82b8 100644
--- a/src/log.c
+++ b/src/log.c
@@ -9,11 +9,8 @@
  */
 #include <config.h>
 
-#include "i3.h"
-#include "libi3.h"
-#include "log.h"
+#include "all.h"
 #include "shmlog.h"
-#include "util.h"
 
 #include <errno.h>
 #include <fcntl.h>
diff --git a/src/main.c b/src/main.c
index 95781d0c..4f4c3fd6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -12,7 +12,9 @@
 
 #include <ev.h>
 #include <fcntl.h>
+#include <getopt.h>
 #include <libgen.h>
+#include <locale.h>
 #include <signal.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
@@ -21,6 +23,7 @@
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/un.h>
+#include <unistd.h>
 
 #ifdef I3_ASAN_ENABLED
 #include <sanitizer/lsan_interface.h>
diff --git a/src/render.c b/src/render.c
index 40704f52..bf96e4df 100644
--- a/src/render.c
+++ b/src/render.c
@@ -10,6 +10,8 @@
  */
 #include "all.h"
 
+#include <math.h>
+
 /* Forward declarations */
 static int *precalculate_sizes(Con *con, render_params *p);
 static void render_root(Con *con, Con *fullscreen);
diff --git a/src/sighandler.c b/src/sighandler.c
index a55c505b..c1e6094f 100644
--- a/src/sighandler.c
+++ b/src/sighandler.c
@@ -9,6 +9,7 @@
 
 #include <signal.h>
 #include <sys/wait.h>
+#include <unistd.h>
 
 typedef struct dialog_t {
     xcb_window_t id;
diff --git a/src/startup.c b/src/startup.c
index 759b373c..9b0576e8 100644
--- a/src/startup.c
+++ b/src/startup.c
@@ -16,6 +16,7 @@
 #include <paths.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <unistd.h>
 
 #define SN_API_NOT_YET_FROZEN 1
 #include <libsn/sn-launcher.h>
diff --git a/src/util.c b/src/util.c
index 734018d4..6d8d2ee7 100644
--- a/src/util.c
+++ b/src/util.c
@@ -10,13 +10,16 @@
  */
 #include "all.h"
 
+#include <ctype.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <libgen.h>
+#include <locale.h>
 #include <sys/wait.h>
+#include <unistd.h>
 #if defined(__OpenBSD__)
 #include <sys/cdefs.h>
 #endif
-#include <ctype.h>
-#include <fcntl.h>
-#include <libgen.h>
 
 int min(int a, int b) {
     return (a < b ? a : b);
diff --git a/src/window.c b/src/window.c
index d84f8869..bee3fa66 100644
--- a/src/window.c
+++ b/src/window.c
@@ -9,6 +9,8 @@
  */
 #include "all.h"
 
+#include <math.h>
+
 /*
  * Frees an i3Window and all its members.
  *
diff --git a/src/x.c b/src/x.c
index 712cf89c..e89f5213 100644
--- a/src/x.c
+++ b/src/x.c
@@ -10,6 +10,8 @@
  */
 #include "all.h"
 
+#include <unistd.h>
+
 #ifndef MAX
 #define MAX(x, y) ((x) > (y) ? (x) : (y))
 #endif
diff --git a/src/xcursor.c b/src/xcursor.c
index 9b4996ea..cb98399f 100644
--- a/src/xcursor.c
+++ b/src/xcursor.c
@@ -9,8 +9,7 @@
  */
 #include <config.h>
 
-#include "i3.h"
-#include "xcb.h"
+#include "all.h"
 
 #include <assert.h>
 #include <err.h>
diff --git a/testcases/inject_randr1.5.c b/testcases/inject_randr1.5.c
index 0b751228..9c0b73d4 100644
--- a/testcases/inject_randr1.5.c
+++ b/testcases/inject_randr1.5.c
@@ -16,6 +16,7 @@
 
 #include <ev.h>
 #include <fcntl.h>
+#include <getopt.h>
 #include <libgen.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
@@ -25,6 +26,7 @@
 #include <sys/types.h>
 #include <sys/un.h>
 #include <sys/wait.h>
+#include <unistd.h>
 
 static void uds_connection_cb(EV_P_ ev_io *w, int revents);
 static void read_client_setup_request_cb(EV_P_ ev_io *w, int revents);