diff --git a/runtime/doc/filetype.txt b/runtime/doc/filetype.txt
index 20bf395..761d667 100644
--- a/runtime/doc/filetype.txt
+++ b/runtime/doc/filetype.txt
@@ -1,4 +1,4 @@
-*filetype.txt*	For Vim version 9.1.  Last change: 2025 Mar 15
+*filetype.txt*	For Vim version 9.1.  Last change: 2025 Apr 15
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -158,6 +158,8 @@
 	*.inc		g:filetype_inc
 	*.lsl		g:filetype_lsl
 	*.m		g:filetype_m		|ft-mathematica-syntax|
+	*[mM]makefile,*.mk,*.mak,[mM]akefile*
+			g:make_flavor		|ft-make-syntax|
 	*.markdown,*.mdown,*.mkd,*.mkdn,*.mdwn,*.md
 			g:filetype_md		|ft-pandoc-syntax|
 	*.mod		g:filetype_mod
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 3c3bde2..ae89bd9 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -1,4 +1,4 @@
-*syntax.txt*	For Vim version 9.1.  Last change: 2025 Apr 13
+*syntax.txt*	For Vim version 9.1.  Last change: 2025 Apr 15
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2393,11 +2393,16 @@
 
 	:let make_no_comments = 1
 
-Microsoft Makefile handles variable expansion and comments differently
-(backslashes are not used for escape).  If you see any wrong highlights
-because of this, you can try this: >
+There are various Make implementations, which add extensions other than the
+POSIX specification and thus are mutually incompatible.  If the filename is
+BSDmakefile or GNUmakefile, the corresponding implementation is automatically
+determined; otherwise vim tries to detect it by the file contents.  If you see
+any wrong highlights because of this, you can enforce a flavor by setting one
+of the following: >
 
-	:let make_microsoft = 1
+	:let g:make_flavor = 'bsd'  " or
+	:let g:make_flavor = 'gnu'  " or
+	:let g:make_flavor = 'microsoft'
 
 
 MAPLE						*maple.vim* *ft-maple-syntax*