diff --git a/dlls/msxml3/httprequest.c b/dlls/msxml3/httprequest.c
index 025dbc2d2f5..21bd80caf41 100644
--- a/dlls/msxml3/httprequest.c
+++ b/dlls/msxml3/httprequest.c
@@ -36,10 +36,22 @@ WINE_DEFAULT_DEBUG_CHANNEL(msxml);
 
 #ifdef HAVE_LIBXML2
 
+static const WCHAR MethodGetW[] = {'G','E','T',0};
+static const WCHAR MethodPutW[] = {'P','U','T',0};
+static const WCHAR MethodPostW[] = {'P','O','S','T',0};
+
 typedef struct _httprequest
 {
     const struct IXMLHTTPRequestVtbl *lpVtbl;
     LONG ref;
+
+    BINDVERB verb;
+    BSTR url;
+    BOOL async;
+
+    /* credentials */
+    BSTR user;
+    BSTR password;
 } httprequest;
 
 static inline httprequest *impl_from_IXMLHTTPRequest( IXMLHTTPRequest *iface )
@@ -83,6 +95,9 @@ static ULONG WINAPI httprequest_Release(IXMLHTTPRequest *iface)
     ref = InterlockedDecrement( &This->ref );
     if ( ref == 0 )
     {
+        SysFreeString(This->url);
+        SysFreeString(This->user);
+        SysFreeString(This->password);
         heap_free( This );
     }
 
@@ -158,14 +173,57 @@ static HRESULT WINAPI httprequest_Invoke(IXMLHTTPRequest *iface, DISPID dispIdMe
     return hr;
 }
 
-static HRESULT WINAPI httprequest_open(IXMLHTTPRequest *iface, BSTR bstrMethod, BSTR bstrUrl,
-        VARIANT varAsync, VARIANT bstrUser, VARIANT bstrPassword)
+static HRESULT WINAPI httprequest_open(IXMLHTTPRequest *iface, BSTR method, BSTR url,
+        VARIANT async, VARIANT user, VARIANT password)
 {
     httprequest *This = impl_from_IXMLHTTPRequest( iface );
+    HRESULT hr;
+    VARIANT str;
 
-    FIXME("stub (%p)\n", This);
+    TRACE("(%p)->(%s %s)\n", This, debugstr_w(method), debugstr_w(url));
 
-    return E_NOTIMPL;
+    if (!method || !url) return E_INVALIDARG;
+
+    /* free previously set data */
+    SysFreeString(This->url);
+    SysFreeString(This->user);
+    SysFreeString(This->password);
+    This->url = This->user = This->password = NULL;
+
+    if (lstrcmpiW(method, MethodGetW) == 0)
+    {
+        This->verb = BINDVERB_GET;
+    }
+    else if (lstrcmpiW(method, MethodPutW) == 0)
+    {
+        This->verb = BINDVERB_PUT;
+    }
+    else if (lstrcmpiW(method, MethodPostW) == 0)
+    {
+        This->verb = BINDVERB_POST;
+    }
+    else
+    {
+        FIXME("unsupported request type %s\n", debugstr_w(method));
+        This->verb = -1;
+        return E_FAIL;
+    }
+
+    This->url = SysAllocString(url);
+
+    hr = VariantChangeType(&async, &async, 0, VT_BOOL);
+    This->async = hr == S_OK && V_BOOL(&async) == VARIANT_TRUE;
+
+    VariantInit(&str);
+    hr = VariantChangeType(&str, &user, 0, VT_BSTR);
+    if (hr == S_OK)
+        This->user = V_BSTR(&str);
+
+    hr = VariantChangeType(&str, &password, 0, VT_BSTR);
+    if (hr == S_OK)
+        This->password = V_BSTR(&str);
+
+    return S_OK;
 }
 
 static HRESULT WINAPI httprequest_setRequestHeader(IXMLHTTPRequest *iface, BSTR bstrHeader, BSTR bstrValue)
@@ -324,6 +382,10 @@ HRESULT XMLHTTPRequest_create(IUnknown *pUnkOuter, LPVOID *ppObj)
     req->lpVtbl = &dimimpl_vtbl;
     req->ref = 1;
 
+    req->async = FALSE;
+    req->verb = -1;
+    req->url = req->user = req->password = NULL;
+
     *ppObj = &req->lpVtbl;
 
     TRACE("returning iface %p\n", *ppObj);
diff --git a/dlls/msxml3/tests/domdoc.c b/dlls/msxml3/tests/domdoc.c
index a256c1c6b7d..008c6b7a103 100644
--- a/dlls/msxml3/tests/domdoc.c
+++ b/dlls/msxml3/tests/domdoc.c
@@ -2883,9 +2883,9 @@ static void test_XMLHTTP(void)
         'p','o','s','t','t','e','s','t','.','p','h','p',0};
     static const WCHAR wszExpectedResponse[] = {'F','A','I','L','E','D',0};
     IXMLHttpRequest *pXMLHttpRequest;
-    BSTR bstrResponse, str1, str2;
+    BSTR bstrResponse, method, url;
     VARIANT dummy;
-    VARIANT varfalse;
+    VARIANT async;
     VARIANT varbody;
     HRESULT hr = CoCreateInstance(&CLSID_XMLHTTPRequest, NULL,
                                   CLSCTX_INPROC_SERVER, &IID_IXMLHttpRequest,
@@ -2899,18 +2899,30 @@ static void test_XMLHTTP(void)
     VariantInit(&dummy);
     V_VT(&dummy) = VT_ERROR;
     V_ERROR(&dummy) = DISP_E_MEMBERNOTFOUND;
-    VariantInit(&varfalse);
-    V_VT(&varfalse) = VT_BOOL;
-    V_BOOL(&varfalse) = VARIANT_FALSE;
+    VariantInit(&async);
+    V_VT(&async) = VT_BOOL;
+    V_BOOL(&async) = VARIANT_FALSE;
     V_VT(&varbody) = VT_BSTR;
     V_BSTR(&varbody) = SysAllocString(wszBody);
 
-    str1 = SysAllocString(wszPOST);
-    str2 = SysAllocString(wszUrl);
-    hr = IXMLHttpRequest_open(pXMLHttpRequest, str1, str2, varfalse, dummy, dummy);
-    todo_wine ok(hr == S_OK, "IXMLHttpRequest_open should have succeeded instead of failing with 0x%08x\n", hr);
-    SysFreeString(str1);
-    SysFreeString(str2);
+    method = SysAllocString(wszPOST);
+    url = SysAllocString(wszUrl);
+
+    /* invalid parameters */
+    hr = IXMLHttpRequest_open(pXMLHttpRequest, NULL, NULL, async, dummy, dummy);
+    ok(hr == E_INVALIDARG, "got 0x%08x\n", hr);
+
+    hr = IXMLHttpRequest_open(pXMLHttpRequest, method, NULL, async, dummy, dummy);
+    ok(hr == E_INVALIDARG, "got 0x%08x\n", hr);
+
+    hr = IXMLHttpRequest_open(pXMLHttpRequest, NULL, url, async, dummy, dummy);
+    ok(hr == E_INVALIDARG, "got 0x%08x\n", hr);
+
+    hr = IXMLHttpRequest_open(pXMLHttpRequest, method, url, async, dummy, dummy);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+
+    SysFreeString(method);
+    SysFreeString(url);
 
     hr = IXMLHttpRequest_send(pXMLHttpRequest, varbody);
     if (hr == INET_E_RESOURCE_NOT_FOUND)