diff --git a/i3-config-wizard/main.c b/i3-config-wizard/main.c
index 61db75ecd..9e07d1f7d 100644
--- a/i3-config-wizard/main.c
+++ b/i3-config-wizard/main.c
@@ -10,6 +10,8 @@
  */
 #include <config.h>
 
+#include "libi3.h"
+
 #if defined(__FreeBSD__)
 #include <sys/param.h>
 #endif
@@ -23,17 +25,12 @@
 #define _WITH_GETLINE
 #endif
 
-#include <assert.h>
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <getopt.h>
-#include <glob.h>
 #include <limits.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
@@ -68,7 +65,6 @@
 
 #include "xcb.h"
 xcb_visualtype_t *visual_type = NULL;
-#include "libi3.h"
 
 #define TEXT_PADDING logical_px(4)
 #define WIN_POS_X logical_px(490)
diff --git a/i3-dump-log/main.c b/i3-dump-log/main.c
index e55f1d3c9..e58b0c379 100644
--- a/i3-dump-log/main.c
+++ b/i3-dump-log/main.c
@@ -13,11 +13,9 @@
 #include "shmlog.h"
 
 #include <err.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <i3/ipc.h>
-#include <limits.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <stdint.h>
@@ -25,10 +23,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
-#include <sys/socket.h>
 #include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/un.h>
 #include <unistd.h>
 
 #if !defined(__OpenBSD__)
diff --git a/i3-input/main.c b/i3-input/main.c
index 1a4cbc7d1..dc38b8a6a 100644
--- a/i3-input/main.c
+++ b/i3-input/main.c
@@ -8,10 +8,7 @@
  *                  to i3.
  *
  */
-#include <err.h>
-#include <errno.h>
 #include <getopt.h>
-#include <limits.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -22,7 +19,6 @@
 
 #include <xcb/xcb.h>
 #include <xcb/xcb_aux.h>
-#include <xcb/xcb_event.h>
 #include <xcb/xcb_keysyms.h>
 
 xcb_visualtype_t *visual_type = NULL;
diff --git a/i3-msg/main.c b/i3-msg/main.c
index dd72bd561..0b0ef4e39 100644
--- a/i3-msg/main.c
+++ b/i3-msg/main.c
@@ -17,24 +17,16 @@
 #include "libi3.h"
 
 #include <err.h>
-#include <errno.h>
 #include <getopt.h>
 #include <i3/ipc.h>
-#include <limits.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/socket.h>
-#include <sys/types.h>
-#include <sys/un.h>
 #include <unistd.h>
 
-#include <xcb/xcb.h>
-#include <xcb/xcb_aux.h>
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 /*
  * Having verboselog() and errorlog() is necessary when using libi3.
diff --git a/i3bar/include/common.h b/i3bar/include/common.h
index 222f42dd9..2d763133b 100644
--- a/i3bar/include/common.h
+++ b/i3bar/include/common.h
@@ -9,7 +9,6 @@
 
 #include <config.h>
 
-#include <stdbool.h>
 #include <xcb/xcb.h>
 #include <xcb/xproto.h>
 #include "libi3.h"
@@ -94,5 +93,4 @@ extern TAILQ_HEAD(statusline_head, status_block)
 #include "trayclients.h"
 #include "xcb.h"
 #include "configuration.h"
-#include "libi3.h"
 #include "parse_json_header.h"
diff --git a/i3bar/src/child.c b/i3bar/src/child.c
index 4723dbc57..871c23052 100644
--- a/i3bar/src/child.c
+++ b/i3bar/src/child.c
@@ -20,15 +20,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
-#include <xcb/xcb_keysyms.h>
-#include <yajl/yajl_common.h>
 #include <yajl/yajl_gen.h>
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 /* Global variables for child_*() */
 i3bar_child child;
diff --git a/i3bar/src/config.c b/i3bar/src/config.c
index 48f49b898..5d4bf88a4 100644
--- a/i3bar/src/config.c
+++ b/i3bar/src/config.c
@@ -9,15 +9,12 @@
  */
 #include "common.h"
 
-#include <errno.h>
-#include <i3/ipc.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <X11/Xlib.h>
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 config_t config;
 static char *cur_key;
diff --git a/i3bar/src/ipc.c b/i3bar/src/ipc.c
index d2edfe787..f2c105ac3 100644
--- a/i3bar/src/ipc.c
+++ b/i3bar/src/ipc.c
@@ -13,11 +13,8 @@
 #include <ev.h>
 #include <i3/ipc.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/socket.h>
-#include <sys/un.h>
 #include <unistd.h>
 #ifdef I3_ASAN_ENABLED
 #include <sanitizer/lsan_interface.h>
diff --git a/i3bar/src/main.c b/i3bar/src/main.c
index b3e23cda7..4e729341b 100644
--- a/i3bar/src/main.c
+++ b/i3bar/src/main.c
@@ -7,7 +7,6 @@
  */
 #include "common.h"
 
-#include <errno.h>
 #include <ev.h>
 #include <getopt.h>
 #include <glob.h>
@@ -15,7 +14,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 
 struct ev_loop *main_loop;
 
diff --git a/i3bar/src/mode.c b/i3bar/src/mode.c
index 1f0e22fa8..13d02110a 100644
--- a/i3bar/src/mode.c
+++ b/i3bar/src/mode.c
@@ -9,13 +9,10 @@
  */
 #include "common.h"
 
-#include <errno.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 /* A datatype to pass through the callbacks to save the state */
 struct mode_json_params {
diff --git a/i3bar/src/outputs.c b/i3bar/src/outputs.c
index f1dab9f16..46b9c9548 100644
--- a/i3bar/src/outputs.c
+++ b/i3bar/src/outputs.c
@@ -10,13 +10,11 @@
 #include "common.h"
 
 #include <errno.h>
-#include <i3/ipc.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 /* A datatype to pass through the callbacks to save the state */
 struct outputs_json_params {
diff --git a/i3bar/src/parse_json_header.c b/i3bar/src/parse_json_header.c
index cd857d917..c74a62fee 100644
--- a/i3bar/src/parse_json_header.c
+++ b/i3bar/src/parse_json_header.c
@@ -10,23 +10,10 @@
  */
 #include "common.h"
 
-#include <err.h>
-#include <errno.h>
-#include <ev.h>
-#include <fcntl.h>
 #include <signal.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <unistd.h>
 
-#include <yajl/yajl_common.h>
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 static enum {
     KEY_VERSION,
diff --git a/i3bar/src/workspaces.c b/i3bar/src/workspaces.c
index 51b863ca4..bd56f5d09 100644
--- a/i3bar/src/workspaces.c
+++ b/i3bar/src/workspaces.c
@@ -9,13 +9,10 @@
  */
 #include "common.h"
 
-#include <errno.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 /* A datatype to pass through the callbacks to save the state */
 struct workspaces_json_params {
diff --git a/i3bar/src/xcb.c b/i3bar/src/xcb.c
index 0b0e23b09..5241f1410 100644
--- a/i3bar/src/xcb.c
+++ b/i3bar/src/xcb.c
@@ -10,24 +10,14 @@
 #include "common.h"
 
 #include <err.h>
-#include <errno.h>
 #include <ev.h>
-#include <fcntl.h>
 #include <i3/ipc.h>
-#include <limits.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 
-#include <X11/XKBlib.h>
-#include <X11/Xlib.h>
-#include <X11/extensions/XKB.h>
-#include <xcb/xcb.h>
 #include <xcb/xcb_aux.h>
 #include <xcb/xcb_cursor.h>
 #include <xcb/xkb.h>
-#include <xcb/xproto.h>
 
 #ifdef I3_ASAN_ENABLED
 #include <sanitizer/lsan_interface.h>
diff --git a/libi3/draw_util.c b/libi3/draw_util.c
index 710c536a3..313dc29ac 100644
--- a/libi3/draw_util.c
+++ b/libi3/draw_util.c
@@ -8,8 +8,6 @@
  */
 #include "libi3.h"
 
-#include <cairo/cairo-xcb.h>
-#include <err.h>
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/libi3/fake_configure_notify.c b/libi3/fake_configure_notify.c
index e79a748b2..5d87c3dac 100644
--- a/libi3/fake_configure_notify.c
+++ b/libi3/fake_configure_notify.c
@@ -7,7 +7,6 @@
  */
 #include "libi3.h"
 
-#include <stdbool.h>
 #include <stdlib.h>
 
 #include <xcb/xcb.h>
diff --git a/libi3/font.c b/libi3/font.c
index e89455240..5ed58b8d7 100644
--- a/libi3/font.c
+++ b/libi3/font.c
@@ -11,7 +11,6 @@
 #include <cairo/cairo-xcb.h>
 #include <err.h>
 #include <pango/pangocairo.h>
-#include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/libi3/format_placeholders.c b/libi3/format_placeholders.c
index 99fa3055a..71870a7b1 100644
--- a/libi3/format_placeholders.c
+++ b/libi3/format_placeholders.c
@@ -7,7 +7,6 @@
  */
 #include "libi3.h"
 
-#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/libi3/get_exe_path.c b/libi3/get_exe_path.c
index 762b4965e..3b46ef82f 100644
--- a/libi3/get_exe_path.c
+++ b/libi3/get_exe_path.c
@@ -8,8 +8,6 @@
 #include "libi3.h"
 
 #include <errno.h>
-#include <limits.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/libi3/get_process_filename.c b/libi3/get_process_filename.c
index 6e155ea8a..21429ec36 100644
--- a/libi3/get_process_filename.c
+++ b/libi3/get_process_filename.c
@@ -7,15 +7,10 @@
  */
 #include "libi3.h"
 
-#include <assert.h>
 #include <err.h>
 #include <pwd.h>
-#include <stdbool.h>
-#include <stdint.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
-#include <sys/types.h>
 #include <unistd.h>
 
 /*
diff --git a/libi3/ipc_connect.c b/libi3/ipc_connect.c
index 614ccdf38..871fe083b 100644
--- a/libi3/ipc_connect.c
+++ b/libi3/ipc_connect.c
@@ -12,9 +12,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
-#include <sys/types.h>
 #include <sys/un.h>
-#include <unistd.h>
 
 /*
  * Connects to the i3 IPC socket and returns the file descriptor for the
diff --git a/libi3/ipc_recv_message.c b/libi3/ipc_recv_message.c
index 6364b16d0..516405b00 100644
--- a/libi3/ipc_recv_message.c
+++ b/libi3/ipc_recv_message.c
@@ -11,8 +11,6 @@
 #include <i3/ipc.h>
 #include <inttypes.h>
 #include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
diff --git a/libi3/ipc_send_message.c b/libi3/ipc_send_message.c
index 106db348e..4faeea7fd 100644
--- a/libi3/ipc_send_message.c
+++ b/libi3/ipc_send_message.c
@@ -7,13 +7,8 @@
  */
 #include "libi3.h"
 
-#include <err.h>
-#include <errno.h>
 #include <i3/ipc.h>
 #include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
 
 /*
  * Formats a message (payload) of the given size and type and sends it to i3 via
diff --git a/libi3/is_debug_build.c b/libi3/is_debug_build.c
index afd06237c..cb53407ec 100644
--- a/libi3/is_debug_build.c
+++ b/libi3/is_debug_build.c
@@ -7,7 +7,6 @@
  */
 #include "libi3.h"
 
-#include <stdbool.h>
 #include <string.h>
 
 /*
diff --git a/libi3/root_atom_contents.c b/libi3/root_atom_contents.c
index 134733a2d..6feb31bc8 100644
--- a/libi3/root_atom_contents.c
+++ b/libi3/root_atom_contents.c
@@ -7,10 +7,7 @@
  */
 #include "libi3.h"
 
-#include <limits.h>
 #include <math.h>
-#include <stdbool.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/libi3/safewrappers.c b/libi3/safewrappers.c
index d4225ffe0..767a0f05e 100644
--- a/libi3/safewrappers.c
+++ b/libi3/safewrappers.c
@@ -9,8 +9,6 @@
 
 #include <err.h>
 #include <errno.h>
-#include <stdarg.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/libi3/strndup.c b/libi3/strndup.c
index 533958d2e..a0e87cf6e 100644
--- a/libi3/strndup.c
+++ b/libi3/strndup.c
@@ -8,7 +8,6 @@
 #include "libi3.h"
 
 #include <string.h>
-#include <sys/types.h>
 
 #ifndef HAVE_strndup
 /*
diff --git a/libi3/ucs2_conversion.c b/libi3/ucs2_conversion.c
index c651cdb32..c74672395 100644
--- a/libi3/ucs2_conversion.c
+++ b/libi3/ucs2_conversion.c
@@ -8,7 +8,6 @@
 #include "libi3.h"
 
 #include <err.h>
-#include <errno.h>
 #include <iconv.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/click.c b/src/click.c
index 7cd32e111..64d78315d 100644
--- a/src/click.c
+++ b/src/click.c
@@ -9,12 +9,8 @@
  */
 #include "all.h"
 
-#include <math.h>
 #include <time.h>
 
-#include <X11/XKBlib.h>
-#include <xcb/xcb_icccm.h>
-
 typedef enum { CLICK_BORDER = 0,
                CLICK_DECORATION = 1,
                CLICK_INSIDE = 2 } click_destination_t;
diff --git a/src/commands.c b/src/commands.c
index c96651d09..fa15c33ff 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -11,8 +11,6 @@
 #include "shmlog.h"
 
 #include <fcntl.h>
-#include <float.h>
-#include <stdarg.h>
 #include <stdint.h>
 #include <unistd.h>
 
diff --git a/src/commands_parser.c b/src/commands_parser.c
index 35005d0e1..6c7914151 100644
--- a/src/commands_parser.c
+++ b/src/commands_parser.c
@@ -25,13 +25,6 @@
  */
 #include "all.h"
 
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
 // Macros to make the YAJL API a bit easier to use.
 #define y(x, ...) (command_output.json_gen != NULL ? yajl_gen_##x(command_output.json_gen, ##__VA_ARGS__) : 0)
 #define ystr(str) (command_output.json_gen != NULL ? yajl_gen_string(command_output.json_gen, (unsigned char *)str, strlen(str)) : 0)
diff --git a/src/config_directives.c b/src/config_directives.c
index 4f9e415fc..c039e35f2 100644
--- a/src/config_directives.c
+++ b/src/config_directives.c
@@ -9,9 +9,6 @@
  */
 #include "all.h"
 
-#include <float.h>
-#include <stdarg.h>
-
 /*******************************************************************************
  * Criteria functions.
  ******************************************************************************/
diff --git a/src/display_version.c b/src/display_version.c
index 1fff8b8e4..0185d1ed0 100644
--- a/src/display_version.c
+++ b/src/display_version.c
@@ -11,11 +11,6 @@
 #include "all.h"
 
 #include <fcntl.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/un.h>
-#include <sys/wait.h>
 #include <time.h>
 
 static bool human_readable_key, loaded_config_file_name_key;
diff --git a/src/handlers.c b/src/handlers.c
index c49ebf77c..fa892cc47 100644
--- a/src/handlers.c
+++ b/src/handlers.c
@@ -10,7 +10,6 @@
  */
 #include "all.h"
 
-#include <float.h>
 #include <sys/time.h>
 #include <time.h>
 
diff --git a/src/load_layout.c b/src/load_layout.c
index b69b388c8..ccf965daa 100644
--- a/src/load_layout.c
+++ b/src/load_layout.c
@@ -10,10 +10,7 @@
  */
 #include "all.h"
 
-#include <yajl/yajl_common.h>
-#include <yajl/yajl_gen.h>
 #include <yajl/yajl_parse.h>
-#include <yajl/yajl_version.h>
 
 /* TODO: refactor the whole parsing thing */
 
diff --git a/src/main.c b/src/main.c
index c64bf43d7..95781d0cb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -13,6 +13,7 @@
 #include <ev.h>
 #include <fcntl.h>
 #include <libgen.h>
+#include <signal.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
diff --git a/src/manage.c b/src/manage.c
index da5751dc6..5f860d4ae 100644
--- a/src/manage.c
+++ b/src/manage.c
@@ -8,9 +8,6 @@
  *
  */
 #include "all.h"
-#include "yajl_utils.h"
-
-#include <yajl/yajl_gen.h>
 
 /*
  * Match frame and window depth. This is needed because X will refuse to reparent a
diff --git a/src/sighandler.c b/src/sighandler.c
index 90e6c798d..a55c505b2 100644
--- a/src/sighandler.c
+++ b/src/sighandler.c
@@ -7,14 +7,9 @@
  */
 #include "all.h"
 
-#include <ev.h>
-#include <iconv.h>
 #include <signal.h>
 #include <sys/wait.h>
 
-#include <X11/keysym.h>
-#include <xcb/xcb_event.h>
-
 typedef struct dialog_t {
     xcb_window_t id;
     xcb_colormap_t colormap;
diff --git a/src/util.c b/src/util.c
index a21c7e5fb..734018d4c 100644
--- a/src/util.c
+++ b/src/util.c
@@ -10,7 +10,6 @@
  */
 #include "all.h"
 
-#include <stdarg.h>
 #include <sys/wait.h>
 #if defined(__OpenBSD__)
 #include <sys/cdefs.h>
@@ -18,12 +17,6 @@
 #include <ctype.h>
 #include <fcntl.h>
 #include <libgen.h>
-#include <pwd.h>
-
-#include <yajl/yajl_version.h>
-
-#define SN_API_NOT_YET_FROZEN 1
-#include <libsn/sn-launcher.h>
 
 int min(int a, int b) {
     return (a < b ? a : b);