diff --git a/dlls/winhttp/main.c b/dlls/winhttp/main.c
index 519c24c8959..4e7328aee55 100644
--- a/dlls/winhttp/main.c
+++ b/dlls/winhttp/main.c
@@ -213,3 +213,14 @@ BOOL WINAPI WinHttpReceiveResponse (HINTERNET hRequest, LPVOID lpReserved)
     SetLastError(ERROR_NOT_SUPPORTED);
     return FALSE;
 }
+
+/***********************************************************************
+ *          WinHttpSetOption (winhttp.@)
+ */
+BOOL WINAPI WinHttpSetOption (HINTERNET hInternet, DWORD dwOption, LPVOID lpBuffer, DWORD dwBufferLength)
+{
+    FIXME("stub\n");
+
+    SetLastError(ERROR_NOT_SUPPORTED);
+    return FALSE;
+}
diff --git a/dlls/winhttp/winhttp.spec b/dlls/winhttp/winhttp.spec
index ee7e8cf2261..a907a4bfe0b 100644
--- a/dlls/winhttp/winhttp.spec
+++ b/dlls/winhttp/winhttp.spec
@@ -23,7 +23,7 @@
 @ stdcall WinHttpSendRequest(ptr wstr long ptr long long ptr)
 @ stub WinHttpSetCredentials
 @ stub WinHttpSetDefaultProxyConfiguration
-@ stub WinHttpSetOption
+@ stdcall WinHttpSetOption(ptr long ptr long)
 @ stub WinHttpSetStatusCallback
 @ stub WinHttpSetTimeouts
 @ stub WinHttpTimeFromSystemTime