diff --git a/inc/ufsdefs.h b/inc/ufsdefs.h
index ca95197..e90cda7 100644
--- a/inc/ufsdefs.h
+++ b/inc/ufsdefs.h
@@ -14,4 +14,8 @@ int lisppathname(char *fullname, char *lispname, int dirp, int versionp);
 int quote_fname(char *file);
 int quote_fname_ufs(char *file);
 int quote_dname(char *dir);
+#ifdef DOS
+init_host_filesystem(void);
+exit_host_filesystem(void);
+#endif
 #endif
diff --git a/src/ufs.c b/src/ufs.c
index d3e9b56..de9b962 100644
--- a/src/ufs.c
+++ b/src/ufs.c
@@ -72,7 +72,7 @@ int Dummy_errno; /* If errno cell is not provided by Lisp, dummy_errno is used.
 
 #ifdef DOS
 
-void (*prev_int_24)(); /* keeps address of previous 24 handlr*/
+void (*prev_int_24)(void); /* keeps address of previous 24 handlr*/
 #pragma interrupt(Int24)
 
 /*
@@ -105,7 +105,7 @@ void Int24(void) {
  * Description: Initialize the hosts filesystem by installing
  *        the "critical error handler".
  */
-init_host_filesystem() {
+init_host_filesystem(void) {
   prev_int_24 = _dos_getvect(0x24); /* get addr of current handler, if any */
   _dos_setvect(0x24, Int24);        /* hook our int handler to interrupt   */
   _dpmi_lockregion((void *)prev_int_24, sizeof(prev_int_24));
@@ -118,7 +118,7 @@ init_host_filesystem() {
  * Description: Cleanup the filesystem specific patches.
  *
  */
-exit_host_filesystem() {
+exit_host_filesystem(void) {
   _dos_setvect(0x24, prev_int_24); /* unhook our handlr, install previous*/
   _dpmi_unlockregion((void *)prev_int_24, sizeof(prev_int_24));
   _dpmi_unlockregion((void *)&Int24, 4096);