diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index d0a078f..5aec6fb 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -160,7 +160,7 @@
     cmakecache: ['CMakeCache.txt'],
     cmod: ['file.cmod'],
     cmusrc: ['any/.cmus/autosave', 'any/.cmus/rc', 'any/.cmus/command-history', 'any/.cmus/file.theme', 'any/cmus/rc', 'any/cmus/file.theme', '/.cmus/autosave', '/.cmus/command-history', '/.cmus/file.theme', '/.cmus/rc', '/cmus/file.theme', '/cmus/rc'],
-    cobol: ['file.cbl', 'file.cob', 'file.lib'],
+    cobol: ['file.cbl', 'file.cob'],
     coco: ['file.atg'],
     conaryrecipe: ['file.recipe'],
     conf: ['auto.master', 'file.conf', 'texdoc.cnf', '.x11vncrc', '.chktexrc', '.ripgreprc', 'ripgreprc', 'file.ctags', '.mbsyncrc'],
@@ -256,6 +256,7 @@
     factor: ['file.factor'],
     falcon: ['file.fal'],
     fan: ['file.fan', 'file.fwt'],
+    faust: ['file.dsp', 'file.lib'],
     fennel: ['file.fnl'],
     fetchmail: ['.fetchmailrc'],
     fgl: ['file.4gl', 'file.4gh', 'file.m4gl'],
@@ -420,7 +421,7 @@
     mail: ['snd.123', '.letter', '.letter.123', '.followup', '.article', '.article.123', 'pico.123', 'mutt-xx-xxx', 'muttng-xx-xxx', 'ae123.txt', 'file.eml', 'reportbug-file'],
     mailaliases: ['/etc/mail/aliases', '/etc/aliases', 'any/etc/aliases', 'any/etc/mail/aliases'],
     mailcap: ['.mailcap', 'mailcap'],
-    make: ['file.mk', 'file.mak', 'file.dsp', 'makefile', 'Makefile', 'makefile-file', 'Makefile-file', 'some-makefile', 'some-Makefile', 'Kbuild'],
+    make: ['file.mk', 'file.mak', 'makefile', 'Makefile', 'makefile-file', 'Makefile-file', 'some-makefile', 'some-Makefile', 'Kbuild'],
     mallard: ['file.page'],
     man: ['file.man'],
     manconf: ['/etc/man.conf', 'man.config', 'any/etc/man.conf'],
@@ -2401,6 +2402,32 @@
   filetype off
 endfunc
 
+func Test_dsp_file()
+  filetype on
+
+  " Microsoft Developer Studio Project file
+
+  call writefile(['# Microsoft Developer Studio Project File'], 'Xfile.dsp', 'D')
+  split Xfile.dsp
+  call assert_equal('make', &filetype)
+  bwipe!
+
+  let g:filetype_dsp = 'make'
+  split test.dsp
+  call assert_equal('make', &filetype)
+  bwipe!
+  unlet g:filetype_dsp
+
+  " Faust
+
+  call writefile(['this is a fallback'], 'Xfile.dsp')
+  split Xfile.dsp
+  call assert_equal('faust', &filetype)
+  bwipe!
+
+  filetype off
+endfunc
+
 func Test_vba_file()
   filetype on
 
diff --git a/src/version.c b/src/version.c
index 0d8b57d..44d0214 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    505,
+/**/
     504,
 /**/
     503,