diff --git a/bio.go b/bio.go
index d012e99..1be93aa 100644
--- a/bio.go
+++ b/bio.go
@@ -21,7 +21,9 @@ package openssl
 #include <openssl/bio.h>
 
 extern int cbioNew(BIO *b);
-extern int cbioFree(BIO *b);
+static int cbioFree(BIO *b) {
+	return 1;
+}
 
 extern int writeBioWrite(BIO *b, char *buf, int size);
 extern long writeBioCtrl(BIO *b, int cmd, long arg1, void *arg2);
@@ -97,11 +99,6 @@ func cbioNew(b *C.BIO) C.int {
 	return 1
 }
 
-//export cbioFree
-func cbioFree(b *C.BIO) C.int {
-	return 1
-}
-
 type writeBio struct {
 	data_mtx        sync.Mutex
 	op_mtx          sync.Mutex