diff --git a/include/winhttp.h b/include/winhttp.h
index ef2caff8ec0..cedcea323a2 100644
--- a/include/winhttp.h
+++ b/include/winhttp.h
@@ -62,6 +62,72 @@ typedef int INTERNET_SCHEME, *LPINTERNET_SCHEME;
 
 #define ERROR_WINHTTP_AUTODETECTION_FAILED     (WINHTTP_ERROR_BASE + 180)
 
+/* flags for WinHttp{Set/Query}Options */
+#define WINHTTP_FIRST_OPTION                         WINHTTP_OPTION_CALLBACK
+#define WINHTTP_OPTION_CALLBACK                       1
+#define WINHTTP_OPTION_RESOLVE_TIMEOUT                2
+#define WINHTTP_OPTION_CONNECT_TIMEOUT                3
+#define WINHTTP_OPTION_CONNECT_RETRIES                4
+#define WINHTTP_OPTION_SEND_TIMEOUT                   5
+#define WINHTTP_OPTION_RECEIVE_TIMEOUT                6
+#define WINHTTP_OPTION_RECEIVE_RESPONSE_TIMEOUT       7
+#define WINHTTP_OPTION_HANDLE_TYPE                    9
+#define WINHTTP_OPTION_READ_BUFFER_SIZE              12
+#define WINHTTP_OPTION_WRITE_BUFFER_SIZE             13
+#define WINHTTP_OPTION_PARENT_HANDLE                 21
+#define WINHTTP_OPTION_EXTENDED_ERROR                24
+#define WINHTTP_OPTION_SECURITY_FLAGS                31
+#define WINHTTP_OPTION_SECURITY_CERTIFICATE_STRUCT   32
+#define WINHTTP_OPTION_URL                           34
+#define WINHTTP_OPTION_SECURITY_KEY_BITNESS          36
+#define WINHTTP_OPTION_PROXY                         38
+#define WINHTTP_OPTION_USER_AGENT                    41
+#define WINHTTP_OPTION_CONTEXT_VALUE                 45
+#define WINHTTP_OPTION_CLIENT_CERT_CONTEXT           47
+#define WINHTTP_OPTION_REQUEST_PRIORITY              58
+#define WINHTTP_OPTION_HTTP_VERSION                  59
+#define WINHTTP_OPTION_DISABLE_FEATURE               63
+#define WINHTTP_OPTION_CODEPAGE                      68
+#define WINHTTP_OPTION_MAX_CONNS_PER_SERVER          73
+#define WINHTTP_OPTION_MAX_CONNS_PER_1_0_SERVER      74
+#define WINHTTP_OPTION_AUTOLOGON_POLICY              77
+#define WINHTTP_OPTION_SERVER_CERT_CONTEXT           78
+#define WINHTTP_OPTION_ENABLE_FEATURE                79
+#define WINHTTP_OPTION_WORKER_THREAD_COUNT           80
+#define WINHTTP_OPTION_PASSPORT_COBRANDING_TEXT      81
+#define WINHTTP_OPTION_PASSPORT_COBRANDING_URL       82
+#define WINHTTP_OPTION_CONFIGURE_PASSPORT_AUTH       83
+#define WINHTTP_OPTION_SECURE_PROTOCOLS              84
+#define WINHTTP_OPTION_ENABLETRACING                 85
+#define WINHTTP_OPTION_PASSPORT_SIGN_OUT             86
+#define WINHTTP_OPTION_PASSPORT_RETURN_URL           87
+#define WINHTTP_OPTION_REDIRECT_POLICY               88
+#define WINHTTP_OPTION_MAX_HTTP_AUTOMATIC_REDIRECTS  89
+#define WINHTTP_OPTION_MAX_HTTP_STATUS_CONTINUE      90
+#define WINHTTP_OPTION_MAX_RESPONSE_HEADER_SIZE      91
+#define WINHTTP_OPTION_MAX_RESPONSE_DRAIN_SIZE       92
+#define WINHTTP_OPTION_CONNECTION_INFO               93
+#define WINHTTP_OPTION_CLIENT_CERT_ISSUER_LIST       94
+#define WINHTTP_OPTION_SPN                           96
+#define WINHTTP_OPTION_GLOBAL_PROXY_CREDS            97
+#define WINHTTP_OPTION_GLOBAL_SERVER_CREDS           98
+#define WINHTTP_OPTION_UNLOAD_NOTIFY_EVENT           99
+#define WINHTTP_OPTION_REJECT_USERPWD_IN_URL         100
+#define WINHTTP_OPTION_USE_GLOBAL_SERVER_CREDENTIALS 101
+#define WINHTTP_LAST_OPTION                          WINHTTP_OPTION_USE_GLOBAL_SERVER_CREDENTIALS
+#define WINHTTP_OPTION_USERNAME                      0x1000
+#define WINHTTP_OPTION_PASSWORD                      0x1001
+#define WINHTTP_OPTION_PROXY_USERNAME                0x1002
+#define WINHTTP_OPTION_PROXY_PASSWORD                0x1003
+
+/* Options for WinHttpOpenRequest */
+#define WINHTTP_NO_REFERER             NULL
+#define WINHTTP_DEFAULT_ACCEPT_TYPES   NULL
+
+/* Options for WinHttpSendRequest */
+#define WINHTTP_NO_ADDITIONAL_HEADERS   NULL
+#define WINHTTP_NO_REQUEST_DATA         NULL
+
 typedef struct
 {
     DWORD   dwStructSize;