diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 2757103..8350e06 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -108,6 +108,13 @@
 #include <unistd.h>
 #endif
 
+#if defined(sun) && !defined(__SVR4)
+/* SunOS 4.1.4 doesn't have prototypes for these: */
+extern int rename(const char *, const char *);
+extern int pclose(FILE *);
+extern int fclose(FILE *);
+#endif
+
 #ifdef NeXT
 /* NeXT's <unistd.h> and <utime.h> aren't worth much */
 #undef HAVE_UNISTD_H