diff --git a/.clang-format b/.clang-format
index 5e31777265..a37e2fdbd1 100644
--- a/.clang-format
+++ b/.clang-format
@@ -36,8 +36,16 @@ BraceWrapping:
   BeforeElse:      false
   IndentBraces:    false
 PointerAlignment: Right
-SortIncludes: false
+SortIncludes: true
 Cpp11BracedListStyle: false
+IncludeCategories:
+  - Regex:           '<[/[:alnum:].]+>'
+    Priority:        0
+  - Regex:           '^"(nvim|vim)/'
+    Priority:        1
+    SortPriority:    1
+    CaseSensitive:   false
+IndentPPDirectives: AfterHash
 SpaceBeforeParens: ControlStatementsExceptControlMacros
 ForEachMacros:
   - FOR_ALL_AUEVENTS
@@ -54,4 +62,4 @@ ForEachMacros:
   - RBUFFER_EACH_REVERSE
   - RBUFFER_UNTIL_EMPTY
   - RBUFFER_UNTIL_FULL
-  - kl_iter
+  - kl_iter
\ No newline at end of file
diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index 3dc3d3d7a9..783cec4d60 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -4,7 +4,6 @@
 // autocmd.c: Autocommand related functions
 #include <signal.h>
 
-#include "lauxlib.h"
 #include "nvim/api/private/helpers.h"
 #include "nvim/ascii.h"
 #include "nvim/autocmd.h"
@@ -27,6 +26,9 @@
 #include "nvim/state.h"
 #include "nvim/ui_compositor.h"
 #include "nvim/vim.h"
+#include "nvim/window.h"
+
+#include "lauxlib.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "auevents_name_map.generated.h"
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 8840813b84..99a24464a8 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -25,7 +25,6 @@
 #include <string.h>
 
 #include "nvim/api/private/helpers.h"
-#include "nvim/api/vim.h"
 #include "nvim/ascii.h"
 #include "nvim/assert.h"
 #include "nvim/buffer.h"
@@ -50,7 +49,6 @@
 #include "nvim/garray.h"
 #include "nvim/getchar.h"
 #include "nvim/hashtab.h"
-#include "nvim/highlight.h"
 #include "nvim/highlight_group.h"
 #include "nvim/indent.h"
 #include "nvim/indent_c.h"
@@ -64,13 +62,11 @@
 #include "nvim/os/input.h"
 #include "nvim/os/os.h"
 #include "nvim/os/time.h"
-#include "nvim/os_unix.h"
 #include "nvim/path.h"
 #include "nvim/plines.h"
 #include "nvim/quickfix.h"
 #include "nvim/regexp.h"
 #include "nvim/screen.h"
-#include "nvim/shada.h"
 #include "nvim/sign.h"
 #include "nvim/spell.h"
 #include "nvim/strings.h"
diff --git a/src/nvim/buffer.h b/src/nvim/buffer.h
index 7f4bbcc9e5..b452eb227e 100644
--- a/src/nvim/buffer.h
+++ b/src/nvim/buffer.h
@@ -2,14 +2,11 @@
 #define NVIM_BUFFER_H
 
 #include "nvim/eval.h"
-#include "nvim/ex_cmds_defs.h"  // for exarg_T
 #include "nvim/func_attr.h"
 #include "nvim/macros.h"
 #include "nvim/memline.h"
 #include "nvim/pos.h"  // for linenr_T
 #include "nvim/screen.h"  // for StlClickRecord
-#include "nvim/vim.h"
-#include "nvim/window.h"
 
 // Values for buflist_getfile()
 enum getf_values {
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index d6d5ecc907..8d2f7c4545 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -102,8 +102,6 @@ typedef uint64_t disptick_T;  // display tick type
 
 // for struct memline (it needs memfile_T)
 #include "nvim/memline_defs.h"
-// for struct memfile, bhdr_T, blocknr_T... (it needs buf_T)
-#include "nvim/memfile_defs.h"
 
 // for regprog_T. Needs win_T and buf_T.
 #include "nvim/regexp_defs.h"
diff --git a/src/nvim/buffer_updates.h b/src/nvim/buffer_updates.h
index 961fec879b..3c2635be71 100644
--- a/src/nvim/buffer_updates.h
+++ b/src/nvim/buffer_updates.h
@@ -1,8 +1,8 @@
 #ifndef NVIM_BUFFER_UPDATES_H
 #define NVIM_BUFFER_UPDATES_H
 
-#include "nvim/buffer_defs.h"
-#include "nvim/extmark.h"
+#include "nvim/buffer_defs.h"  // for buf_T
+#include "nvim/extmark.h"      // for bcount_t
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "buffer_updates.h.generated.h"
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 9170dd113a..f572440edc 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -25,7 +25,6 @@
 #include "nvim/eval/funcs.h"
 #include "nvim/eval/typval.h"
 #include "nvim/eval/userfunc.h"
-#include "nvim/ex_cmds2.h"
 #include "nvim/ex_docmd.h"
 #include "nvim/ex_getln.h"
 #include "nvim/file_search.h"
@@ -70,7 +69,7 @@
 #include "nvim/undo.h"
 #include "nvim/version.h"
 #include "nvim/vim.h"
-
+#include "nvim/window.h"
 
 /// Describe data to return from find_some_match()
 typedef enum {
diff --git a/src/nvim/if_cscope.c b/src/nvim/if_cscope.c
index 093ca238f1..e0372c5632 100644
--- a/src/nvim/if_cscope.c
+++ b/src/nvim/if_cscope.c
@@ -32,6 +32,7 @@
 #include "nvim/quickfix.h"
 #include "nvim/strings.h"
 #include "nvim/tag.h"
+#include "nvim/window.h"
 #if defined(UNIX)
 # include <sys/wait.h>
 #endif
diff --git a/src/nvim/sign.c b/src/nvim/sign.c
index a50b4a5a99..6685c2f231 100644
--- a/src/nvim/sign.c
+++ b/src/nvim/sign.c
@@ -5,6 +5,7 @@
 // sign.c: functions for managing with signs
 //
 
+#include "nvim/sign.h"
 
 #include "nvim/ascii.h"
 #include "nvim/buffer.h"
@@ -17,9 +18,9 @@
 #include "nvim/move.h"
 #include "nvim/option.h"
 #include "nvim/screen.h"
-#include "nvim/sign.h"
 #include "nvim/syntax.h"
 #include "nvim/vim.h"
+#include "nvim/window.h"
 
 /// Struct to hold the sign properties.
 typedef struct sign sign_T;