diff --git a/include/tcclib.h b/include/tcclib.h
index 4ae3ea4..42f8f3f 100644
--- a/include/tcclib.h
+++ b/include/tcclib.h
@@ -18,7 +18,7 @@ void *realloc(void *ptr, size_t size);
 int atoi(const char *nptr);
 long int strtol(const char *nptr, char **endptr, int base);
 unsigned long int strtoul(const char *nptr, char **endptr, int base);
-int exit(int);
+void exit(int);
 
 /* stdio.h */
 typedef struct __FILE FILE;