diff --git a/src/os_win32.c b/src/os_win32.c
index 5a84824..9fa806e 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -481,7 +481,7 @@
 				       = null_libintl_bind_textdomain_codeset;
 
     int
-dyn_libintl_init()
+dyn_libintl_init(void)
 {
     int i;
     static struct
@@ -543,7 +543,7 @@
 }
 
     void
-dyn_libintl_end()
+dyn_libintl_end(void)
 {
     if (hLibintlDLL)
 	FreeLibrary(hLibintlDLL);