diff --git a/NEWS b/NEWS
index bde353a2488..976f031effe 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,7 @@ PHP                                                                        NEWS
   . Fixed bug GH-9918 (License information for xxHash is not included in
     README.REDIST.BINS file). (Akama Hitoshi)
   . Fixed bug GH-9650 (Can't initialize heap: [0x000001e7]). (Michael Voříšek)
+  . Fixed potentially undefined behavior in Windows ftok(3) emulation. (cmb)
 
 - MBString:
   . Fixed bug GH-9535 (The behavior of mb_strcut in mbstring has been changed in
diff --git a/win32/ftok.c b/win32/ftok.c
index 3a545375fa0..76e47ec48e1 100644
--- a/win32/ftok.c
+++ b/win32/ftok.c
@@ -51,7 +51,7 @@ ftok(const char *pathname, int proj_id)
 		return (key_t)-1;
 	}
 
-	ret = (key_t) ((proj_id & 0xff) << 24 | (st.st_dev & 0xff) << 16 | ((bhfi.nFileIndexLow | (__int64)bhfi.nFileIndexHigh << 32) & 0xffff));
+	ret = (key_t) ((proj_id & 0xff) << 24 | (st.st_dev & 0xff) << 16 | (bhfi.nFileIndexLow & 0xffff));
 
 	CloseHandle(fh);
 	PHP_WIN32_IOUTIL_CLEANUP_W()