diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index 7740d8f..bd1d2e9 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -1091,7 +1091,9 @@
 
 " Modsim III (or LambdaProlog)
 au BufNewFile,BufRead *.mod
-	\ if getline(1) =~ '\<module\>' |
+	\ if expand("<afile>") =~ '\<go.mod$' |
+	\   setf gomod |
+	\ elseif getline(1) =~ '\<module\>' |
 	\   setf lprolog |
 	\ else |
 	\   setf modsim3 |
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index cd82e38..719d690 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -204,6 +204,7 @@
     \ 'gnash': ['gnashrc', '.gnashrc', 'gnashpluginrc', '.gnashpluginrc'],
     \ 'gnuplot': ['file.gpi'],
     \ 'go': ['file.go'],
+    \ 'gomod': ['go.mod'],
     \ 'gp': ['file.gp', '.gprc'],
     \ 'gpg': ['/.gnupg/options', '/.gnupg/gpg.conf', '/usr/any/gnupg/options.skel', 'any/.gnupg/gpg.conf', 'any/.gnupg/options', 'any/usr/any/gnupg/options.skel'],
     \ 'grads': ['file.gs'],
diff --git a/src/version.c b/src/version.c
index 7a1fd69..53d3b57 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3873,
+/**/
     3872,
 /**/
     3871,