diff --git a/dlls/mshtml/pluginhost.c b/dlls/mshtml/pluginhost.c
index 8f280c5f5db..9ab0983080b 100644
--- a/dlls/mshtml/pluginhost.c
+++ b/dlls/mshtml/pluginhost.c
@@ -651,8 +651,36 @@ static HRESULT WINAPI PHInPlaceSite_OnInPlaceActivate(IOleInPlaceSiteEx *iface)
 static HRESULT WINAPI PHInPlaceSite_OnUIActivate(IOleInPlaceSiteEx *iface)
 {
     PluginHost *This = impl_from_IOleInPlaceSiteEx(iface);
-    FIXME("(%p)\n", This);
-    return E_NOTIMPL;
+    DISPPARAMS args = {NULL, NULL, 0, 0};
+    IDispatch *disp;
+    ULONG err = 0;
+    VARIANT res;
+    HRESULT hres;
+
+    TRACE("(%p)\n", This);
+
+    if(!This->plugin_unk) {
+        ERR("No plugin object\n");
+        return E_UNEXPECTED;
+    }
+
+    This->ui_active = TRUE;
+
+    hres = IUnknown_QueryInterface(This->plugin_unk, &IID_IDispatch, (void**)&disp);
+    if(FAILED(hres)) {
+        FIXME("Could not get IDispatch iface: %08x\n", hres);
+        return hres;
+    }
+
+    V_VT(&res) = VT_EMPTY;
+    hres = IDispatch_Invoke(disp, DISPID_ENABLED, &IID_NULL, 0/*FIXME*/, DISPATCH_PROPERTYGET, &args, &res, NULL, &err);
+    IDispatch_Release(disp);
+    if(SUCCEEDED(hres)) {
+        FIXME("Got enabled %s\n", debugstr_variant(&res));
+        VariantClear(&res);
+    }
+
+    return S_OK;
 }
 
 static HRESULT WINAPI PHInPlaceSite_GetWindowContext(IOleInPlaceSiteEx *iface,
@@ -1024,8 +1052,11 @@ void detach_plugin_host(PluginHost *host)
     if(!host->doc)
         return;
 
-    if(host->ip_object)
+    if(host->ip_object) {
+        if(host->ui_active)
+            IOleInPlaceObject_UIDeactivate(host->ip_object);
         IOleInPlaceObject_InPlaceDeactivate(host->ip_object);
+    }
 
     if(host->plugin_unk) {
         IOleObject *ole_obj;
diff --git a/dlls/mshtml/pluginhost.h b/dlls/mshtml/pluginhost.h
index c547946903d..65ccb60578f 100644
--- a/dlls/mshtml/pluginhost.h
+++ b/dlls/mshtml/pluginhost.h
@@ -33,8 +33,10 @@ typedef struct {
     IUnknown *plugin_unk;
     IOleInPlaceObject *ip_object;
     CLSID clsid;
+
     HWND hwnd;
     RECT rect;
+    BOOL ui_active;
 
     HTMLDocumentNode *doc;
     struct list entry;
diff --git a/dlls/mshtml/tests/activex.c b/dlls/mshtml/tests/activex.c
index aab13d5be07..a89d7e7702f 100644
--- a/dlls/mshtml/tests/activex.c
+++ b/dlls/mshtml/tests/activex.c
@@ -63,6 +63,8 @@ DEFINE_EXPECT(QuickActivate);
 DEFINE_EXPECT(IPersistPropertyBag_InitNew);
 DEFINE_EXPECT(IPersistPropertyBag_Load);
 DEFINE_EXPECT(Invoke_READYSTATE);
+DEFINE_EXPECT(Invoke_ENABLED);
+DEFINE_EXPECT(Invoke_VALID);
 DEFINE_EXPECT(DoVerb);
 DEFINE_EXPECT(SetExtent);
 DEFINE_EXPECT(GetExtent);
@@ -72,6 +74,7 @@ DEFINE_EXPECT(Close);
 DEFINE_EXPECT(InPlaceObject_GetWindow);
 DEFINE_EXPECT(SetObjectRects);
 DEFINE_EXPECT(InPlaceDeactivate);
+DEFINE_EXPECT(UIDeactivate);
 
 static HWND container_hwnd, plugin_hwnd;
 
@@ -572,6 +575,18 @@ static HRESULT WINAPI Dispatch_Invoke(IDispatch *iface, DISPID dispIdMember, REF
         V_VT(pVarResult) = VT_I4;
         V_I4(pVarResult) = plugin_readystate;
         return S_OK;
+     case DISPID_ENABLED:
+        CHECK_EXPECT2(Invoke_ENABLED);
+        ok(wFlags == DISPATCH_PROPERTYGET, "wFlags = %x\n", wFlags);
+        ok(!pDispParams->cArgs, "pDispParams->cArgs = %d\n", pDispParams->cArgs);
+        ok(!pDispParams->rgvarg, "pDispParams->rgvarg != NULL\n");
+        return DISP_E_MEMBERNOTFOUND;
+    case DISPID_VALID:
+        CHECK_EXPECT(Invoke_VALID);
+        ok(wFlags == DISPATCH_PROPERTYGET, "wFlags = %x\n", wFlags);
+        ok(!pDispParams->cArgs, "pDispParams->cArgs = %d\n", pDispParams->cArgs);
+        ok(!pDispParams->rgvarg, "pDispParams->rgvarg != NULL\n");
+        return DISP_E_MEMBERNOTFOUND;
     default:
         ok(0, "unexpected call %d\n", dispIdMember);
     }
@@ -1003,8 +1018,8 @@ static HRESULT WINAPI OleInPlaceObject_InPlaceDeactivate(IOleInPlaceObjectWindow
 
 static HRESULT WINAPI OleInPlaceObject_UIDeactivate(IOleInPlaceObjectWindowless *iface)
 {
-    ok(0, "unexpected call\n");
-    return E_NOTIMPL;
+    CHECK_EXPECT2(UIDeactivate);
+    return S_OK;
 }
 
 static HRESULT WINAPI OleInPlaceObject_SetObjectRects(IOleInPlaceObjectWindowless *iface,
@@ -1149,6 +1164,22 @@ static const IClassFactoryVtbl ClassFactoryVtbl = {
 
 static IClassFactory activex_cf = { &ClassFactoryVtbl };
 
+static void test_ui_activate(void)
+{
+    IOleInPlaceSite *ip_site;
+    HRESULT hres;
+
+    hres = IOleClientSite_QueryInterface(client_site, &IID_IOleInPlaceSite, (void**)&ip_site);
+    ok(hres == S_OK, "Could not get IOleInPlaceSite iface: %08x\n", hres);
+
+    SET_EXPECT(Invoke_ENABLED);
+    hres = IOleInPlaceSite_OnUIActivate(ip_site);
+    ok(hres == S_OK, "OnUIActivate failed: %08x\n", hres);
+    CHECK_CALLED(Invoke_ENABLED);
+
+    IOleInPlaceSite_Release(ip_site);
+}
+
 static HRESULT cs_qi(REFIID,void **);
 static IOleDocumentView *view;
 
@@ -1747,10 +1778,20 @@ static void test_object_ax(void)
     CHECK_CALLED(InPlaceObject_GetWindow);
     CHECK_CALLED(SetObjectRects);
 
+    test_ui_activate();
+
+    SET_EXPECT(UIDeactivate);
+    SET_EXPECT(Invoke_ENABLED);
+    SET_EXPECT(Invoke_VALID);
     SET_EXPECT(InPlaceDeactivate);
     SET_EXPECT(Close);
     SET_EXPECT(SetClientSite_NULL);
     release_doc(doc);
+    CHECK_CALLED(UIDeactivate);
+    todo_wine
+    CHECK_CALLED(Invoke_ENABLED);
+    todo_wine
+    CHECK_CALLED(Invoke_VALID);
     CHECK_CALLED(InPlaceDeactivate);
     CHECK_CALLED(Close);
     CHECK_CALLED(SetClientSite_NULL);