diff --git a/ext/curl/curl.c b/ext/curl/curl.c
index 627ea593707..3887b61610a 100644
--- a/ext/curl/curl.c
+++ b/ext/curl/curl.c
@@ -174,6 +174,9 @@ PHP_MINIT_FUNCTION(curl)
 	REGISTER_CURL_CONSTANT("CURLOPT_HTTPPROXYTUNNEL", CURLOPT_HTTPPROXYTUNNEL);
 	REGISTER_CURL_CONSTANT("CURLOPT_FILETIME",        CURLOPT_FILETIME);
 	REGISTER_CURL_CONSTANT("CURLOPT_WRITEFUNCTION",   CURLOPT_WRITEFUNCTION);
+	REGISTER_CURL_CONSTANT("CURLOPT_READFUNCTION",    CURLOPT_READFUNCTION);
+	REGISTER_CURL_CONSTANT("CURLOPT_PASSWDFUNCTION",  CURLOPT_PASSWDFUNCTION);
+	REGISTER_CURL_CONSTANT("CURLOPT_HEADERFUNCTION",  CURLOPT_HEADERFUNCTION);
 	REGISTER_CURL_CONSTANT("CURLOPT_MAXREDIRS",       CURLOPT_MAXREDIRS);
 	REGISTER_CURL_CONSTANT("CURLOPT_MAXCONNECTS",     CURLOPT_MAXCONNECTS);
 	REGISTER_CURL_CONSTANT("CURLOPT_CLOSEPOLICY",     CURLOPT_CLOSEPOLICY);