diff --git a/dlls/mshtml/htmlframe.c b/dlls/mshtml/htmlframe.c
index 0c07f0c6775..e451f030453 100644
--- a/dlls/mshtml/htmlframe.c
+++ b/dlls/mshtml/htmlframe.c
@@ -1278,15 +1278,14 @@ static HRESULT WINAPI HTMLIFrameElement2_put_width(IHTMLIFrameElement2 *iface, V
     HTMLIFrame *This = impl_from_IHTMLIFrameElement2(iface);
     nsAString nsstr;
     nsresult nsres;
+    HRESULT hres;
 
     TRACE("(%p)->(%s)\n", This, debugstr_variant(&v));
 
-    if(V_VT(&v) != VT_BSTR) {
-        FIXME("Unsupported %s\n", debugstr_variant(&v));
-        return E_NOTIMPL;
-    }
+    hres = variant_to_nsstr(&v, FALSE, &nsstr);
+    if(FAILED(hres))
+        return hres;
 
-    nsAString_InitDepend(&nsstr, V_BSTR(&v));
     nsres = nsIDOMHTMLIFrameElement_SetWidth(This->framebase.nsiframe, &nsstr);
     nsAString_Finish(&nsstr);
     if(NS_FAILED(nsres)) {
diff --git a/dlls/mshtml/tests/dom.c b/dlls/mshtml/tests/dom.c
index 5ef27ede89c..7b19271ad4c 100644
--- a/dlls/mshtml/tests/dom.c
+++ b/dlls/mshtml/tests/dom.c
@@ -8264,6 +8264,12 @@ static void test_iframe_elem(IHTMLElement *elem)
     test_iframe_width(elem, L"70%");
     test_framebase_src(elem, L"about:blank");
 
+    V_VT(&v) = VT_I4;
+    V_I4(&v) = 110;
+    hres = IHTMLIFrameElement2_put_width(iframe2, v);
+    ok(hres == S_OK, "put_height failed: %08x\n", hres);
+    test_iframe_width(elem, L"110");
+
     str = SysAllocString(L"text/html");
     V_VT(&errv) = VT_ERROR;
     disp = NULL;