diff --git a/src/header.c b/src/header.c
index facb263..5d42b70 100644
--- a/src/header.c
+++ b/src/header.c
@@ -1923,6 +1923,11 @@ write_header(fp, hdr)
 #include <CoreFoundation/CFString.h>
 #include <CoreFoundation/CFStringEncodingExt.h>
 
+#ifdef __APPLE__
+unsigned int CFStringEncodingBytesToUnicode(unsigned long, unsigned long, char*, size_t, unsigned long*, UniChar*, int, unsigned long*);
+unsigned int CFStringEncodingUnicodeToBytes(unsigned long, unsigned long, UniChar*, size_t, unsigned long*, char*, int, unsigned long*);
+#endif /* __APPLE__ */
+
 /* this is not need for Mac OS X v 10.2 later */
 enum {
   kCFStringEncodingAllowLossyConversion = 1,