diff --git a/src/wine-host/bridges/vst3-impls/plug-frame-proxy.cpp b/src/wine-host/bridges/vst3-impls/plug-frame-proxy.cpp
index f7026d25..f1e2b933 100644
--- a/src/wine-host/bridges/vst3-impls/plug-frame-proxy.cpp
+++ b/src/wine-host/bridges/vst3-impls/plug-frame-proxy.cpp
@@ -52,8 +52,18 @@ Vst3PlugFrameProxyImpl::resizeView(Steinberg::IPlugView* /*view*/,
         // We have to use this special sending function here so we can handle
         // calls to `IPlugView::onSize()` from this same thread (the UI thread).
         // See the docstring for more information.
-        return bridge_.send_mutually_recursive_message(YaPlugFrame::ResizeView{
-            .owner_instance_id = owner_instance_id(), .new_size = *newSize});
+        const tresult result =
+            bridge_.send_mutually_recursive_message(YaPlugFrame::ResizeView{
+                .owner_instance_id = owner_instance_id(), .new_size = *newSize});
+
+        // Some hosts (like Carla) don't call onSize() after accepting a
+        // resizeView() request. This causes the plugin to not know about its
+        // new size, so it doesn't draw beyond the original size. Call the
+        // plugin's onSize() ourselves to ensure it knows the new size. If the
+        // host already called onSize(), this will be a harmless duplicate call.
+        bridge_.notify_plugin_on_new_size(owner_instance_id(), *newSize);
+
+        return result;
     } else {
         std::cerr
             << "WARNING: Null pointer passed to 'IPlugFrame::resizeView()'"
diff --git a/src/wine-host/bridges/vst3.cpp b/src/wine-host/bridges/vst3.cpp
index d2eec2f5..b48548e8 100644
--- a/src/wine-host/bridges/vst3.cpp
+++ b/src/wine-host/bridges/vst3.cpp
@@ -1388,6 +1388,26 @@ bool Vst3Bridge::resize_editor(size_t instance_id,
     }
 }
 
+void Vst3Bridge::notify_plugin_on_new_size(size_t instance_id,
+                                           Steinberg::ViewRect& new_size) {
+    const auto& [instance, _] = get_instance(instance_id);
+
+    if (instance.plug_view_instance) {
+        // Skip if the host already called onSize() with this size during
+        // resizeView(). This is detected by checking if last_set_size already
+        // matches new_size (the OnSize handler updates last_set_size).
+        if (instance.last_set_size.getWidth() == new_size.getWidth() &&
+            instance.last_set_size.getHeight() == new_size.getHeight()) {
+            return;
+        }
+
+        instance.plug_view_instance->plug_view->onSize(&new_size);
+
+        // Update last_set_size so getSize() returns consistent values
+        instance.last_set_size = new_size;
+    }
+}
+
 void Vst3Bridge::register_context_menu(Vst3ContextMenuProxyImpl& context_menu) {
     const auto& [owner_instance, _] =
         get_instance(context_menu.owner_instance_id());
diff --git a/src/wine-host/bridges/vst3.h b/src/wine-host/bridges/vst3.h
index 75054893..3bef4c36 100644
--- a/src/wine-host/bridges/vst3.h
+++ b/src/wine-host/bridges/vst3.h
@@ -318,6 +318,14 @@ class Vst3Bridge : public HostBridge {
      */
     bool resize_editor(size_t instance_id, const Steinberg::ViewRect& new_size);
 
+    /**
+     * Notify the plugin of its new size by calling `IPlugView::onSize()`.
+     * This is called after `resize_editor()` for hosts that don't call
+     * `onSize()` after accepting a `resizeView()` request (like Carla).
+     */
+    void notify_plugin_on_new_size(size_t instance_id,
+                                   Steinberg::ViewRect& new_size);
+
     /**
      * Register a context with with `context_menu`'s ID and owner in
      * `object_instances`. This will be called during the constructor of