diff --git a/src/process.h b/src/process.h
index fea56f474639bff5a4bb8df9655cc37b080f3d91..21e1b85bb268729b719c353717c4f99a70b47d15 100644
--- a/src/process.h
+++ b/src/process.h
@@ -123,9 +123,3 @@ extern int synch_process_retcode;
 #ifndef NULL_DEVICE
 #define NULL_DEVICE "/dev/null"
 #endif
-
-/* A string listing the possible suffixes used for executable files,
-   separated by colons.  VMS, MS-DOS, and OS/2 redefine this.  */
-#ifndef EXEC_SUFFIXES
-#define EXEC_SUFFIXES ""
-#endif
diff --git a/src/s/ms-w32.h b/src/s/ms-w32.h
index 7c1c62e3ffd979d46aa5a3b22f0ae709b831c48e..6ca043f2fa6357b901c400472da284bbb9828356 100644
--- a/src/s/ms-w32.h
+++ b/src/s/ms-w32.h
@@ -212,7 +212,6 @@ Boston, MA 02111-1307, USA.  */
 
 /* The null device on Windows NT. */
 #define NULL_DEVICE     "NUL:"
-#define EXEC_SUFFIXES   ".exe:.com:.bat:.cmd:"
 
 #ifndef MAXPATHLEN
 #define MAXPATHLEN      _MAX_PATH
diff --git a/src/s/msdos.h b/src/s/msdos.h
index e7c38048a307160df5296cd9d949c1d327cae094..0862d9fec8ef47781beb22bfcd9cae903cd46e8d 100644
--- a/src/s/msdos.h
+++ b/src/s/msdos.h
@@ -196,7 +196,6 @@ You lose; /* Emacs for DOS must be compiled with DJGPP */
 #define SEPCHAR ';'
 
 #define NULL_DEVICE "nul"
-#define EXEC_SUFFIXES ".exe:.com:.bat:"
 
 #if __DJGPP__ < 2
 #define O_RDONLY        0x0001