diff --git a/ext/curl/interface.c b/ext/curl/interface.c
index d5d20d825652..c9077970bdc0 100644
--- a/ext/curl/interface.c
+++ b/ext/curl/interface.c
@@ -2170,7 +2170,7 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 					/* no need to build the mime structure for empty hashtables;
 					   also works around https://github.com/curl/curl/issues/6455 */
 					curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDS, "");
-					error = curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDSIZE, 0L);
+					error = curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDSIZE_LARGE, (curl_off_t) 0);
 				} else {
 					return build_mime_structure_from_hash(ch, zvalue);
 				}
@@ -2178,7 +2178,7 @@ static zend_result _php_curl_setopt(php_curl *ch, zend_long option, zval *zvalue
 				zend_string *tmp_str;
 				zend_string *str = zval_get_tmp_string(zvalue, &tmp_str);
 				/* with curl 7.17.0 and later, we can use COPYPOSTFIELDS, but we have to provide size before */
-				error = curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDSIZE, ZSTR_LEN(str));
+				error = curl_easy_setopt(ch->cp, CURLOPT_POSTFIELDSIZE_LARGE, (curl_off_t) ZSTR_LEN(str));
 				error = curl_easy_setopt(ch->cp, CURLOPT_COPYPOSTFIELDS, ZSTR_VAL(str));
 				zend_tmp_string_release(tmp_str);
 			}