diff --git a/src/os_mac_conv.c b/src/os_mac_conv.c
index 2c4038e..4f71d65 100644
--- a/src/os_mac_conv.c
+++ b/src/os_mac_conv.c
@@ -31,8 +31,8 @@
 typedef int CFStringRef;
 # endif
 
-static char_u	    *mac_utf16_to_utf8 __ARGS((UniChar *from, size_t fromLen, size_t *actualLen));
-static UniChar	    *mac_utf8_to_utf16 __ARGS((char_u *from, size_t fromLen, size_t *actualLen));
+static char_u	    *mac_utf16_to_utf8(UniChar *from, size_t fromLen, size_t *actualLen);
+static UniChar	    *mac_utf8_to_utf16(char_u *from, size_t fromLen, size_t *actualLen);
 
 /* Converter for composing decomposed HFS+ file paths */
 static TECObjectRef gPathConverter;