diff --git a/patch/patch.cfg b/patch/patch.cfg
index 925213d10..23a344827 100644
--- a/patch/patch.cfg
+++ b/patch/patch.cfg
@@ -717,4 +717,9 @@ patches = [
     # https://github.com/chromiumembedded/cef/issues/3641
     'name': 'win_taskbar_group_3641'
   },
+  {
+    # chrome: win: Disable taskbar decoration for PiP and DevTools windows.
+    # https://github.com/chromiumembedded/cef/issues/3645
+    'name': 'win_taskbar_decorator_3645'
+  },
 ]
diff --git a/patch/patches/win_taskbar_decorator_3645.patch b/patch/patches/win_taskbar_decorator_3645.patch
new file mode 100644
index 000000000..b8ba64c60
--- /dev/null
+++ b/patch/patches/win_taskbar_decorator_3645.patch
@@ -0,0 +1,41 @@
+diff --git chrome/browser/taskbar/taskbar_decorator_win.cc chrome/browser/taskbar/taskbar_decorator_win.cc
+index 20f37cf8b31ee..85569f9a9694c 100644
+--- chrome/browser/taskbar/taskbar_decorator_win.cc
++++ chrome/browser/taskbar/taskbar_decorator_win.cc
+@@ -18,12 +18,14 @@
+ #include "base/strings/utf_string_conversions.h"
+ #include "base/task/thread_pool.h"
+ #include "base/win/scoped_gdi_object.h"
++#include "cef/libcef/features/features.h"
+ #include "chrome/browser/browser_process.h"
+ #include "chrome/browser/profiles/avatar_menu.h"
+ #include "chrome/browser/profiles/profile.h"
+ #include "chrome/browser/profiles/profile_attributes_storage.h"
+ #include "chrome/browser/profiles/profile_avatar_icon_util.h"
+ #include "chrome/browser/profiles/profile_manager.h"
++#include "chrome/browser/ui/views/frame/browser_view.h"
+ #include "skia/ext/font_utils.h"
+ #include "skia/ext/image_operations.h"
+ #include "skia/ext/legacy_display_globals.h"
+@@ -201,6 +203,21 @@ void UpdateTaskbarDecoration(Profile* profile, gfx::NativeWindow window) {
+     return;
+   }
+ 
++#if BUILDFLAG(ENABLE_CEF)
++  if (auto browser_view = BrowserView::GetBrowserViewForNativeWindow(window)) {
++    if (auto browser = browser_view->browser()) {
++      if (browser->cef_delegate() &&
++            (browser->is_type_picture_in_picture() ||
++             browser->is_type_devtools()) &&
++            browser->cef_delegate()->HasViewsHostedOpener()) {
++        // Don't add taskbar decoration.
++        taskbar::DrawTaskbarDecoration(window, nullptr);
++        return;
++      }
++    }
++  }
++#endif  // BUILDFLAG(ENABLE_CEF)
++
+   // We need to draw the taskbar decoration. Even though we have an icon on the
+   // window's relaunch details, we draw over it because the user may have
+   // pinned the badge-less Chrome shortcut which will cause Windows to ignore