diff --git a/include/AModule.hpp b/include/AModule.hpp
index df0165cf..c15efb00 100644
--- a/include/AModule.hpp
+++ b/include/AModule.hpp
@@ -11,6 +11,8 @@ namespace waybar {
 
 class AModule : public IModule {
  public:
+  static constexpr const char *MODULE_CLASS = "module";
+
   virtual ~AModule();
   auto update() -> void override;
   virtual auto refresh(int) -> void{};
diff --git a/src/ALabel.cpp b/src/ALabel.cpp
index c87e3228..7840819d 100644
--- a/src/ALabel.cpp
+++ b/src/ALabel.cpp
@@ -20,6 +20,7 @@ ALabel::ALabel(const Json::Value& config, const std::string& name, const std::st
   if (!id.empty()) {
     label_.get_style_context()->add_class(id);
   }
+  label_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(label_);
   if (config_["max-length"].isUInt()) {
     label_.set_max_width_chars(config_["max-length"].asInt());
diff --git a/src/ASlider.cpp b/src/ASlider.cpp
index a5e3889c..b434be30 100644
--- a/src/ASlider.cpp
+++ b/src/ASlider.cpp
@@ -13,6 +13,7 @@ ASlider::ASlider(const Json::Value& config, const std::string& name, const std::
   if (!id.empty()) {
     scale_.get_style_context()->add_class(id);
   }
+  scale_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(scale_);
   scale_.signal_value_changed().connect(sigc::mem_fun(*this, &ASlider::onValueChanged));
 
diff --git a/src/modules/custom.cpp b/src/modules/custom.cpp
index d628b85d..7f66213d 100644
--- a/src/modules/custom.cpp
+++ b/src/modules/custom.cpp
@@ -176,16 +176,18 @@ auto waybar::modules::Custom::update() -> void {
           }
         }
       }
-      auto classes = label_.get_style_context()->list_classes();
+      auto style = label_.get_style_context();
+      auto classes = style->list_classes();
       for (auto const& c : classes) {
         if (c == id_) continue;
-        label_.get_style_context()->remove_class(c);
+        style->remove_class(c);
       }
       for (auto const& c : class_) {
-        label_.get_style_context()->add_class(c);
+        style->add_class(c);
       }
-      label_.get_style_context()->add_class("flat");
-      label_.get_style_context()->add_class("text-button");
+      style->add_class("flat");
+      style->add_class("text-button");
+      style->add_class(MODULE_CLASS);
       event_box_.show();
     }
   }
diff --git a/src/modules/dwl/tags.cpp b/src/modules/dwl/tags.cpp
index afe658e1..f36ece1d 100644
--- a/src/modules/dwl/tags.cpp
+++ b/src/modules/dwl/tags.cpp
@@ -113,6 +113,7 @@ Tags::Tags(const std::string &id, const waybar::Bar &bar, const Json::Value &con
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
 
   // Default to 9 tags, cap at 32
diff --git a/src/modules/hyprland/workspaces.cpp b/src/modules/hyprland/workspaces.cpp
index 4200f85e..88b5e135 100644
--- a/src/modules/hyprland/workspaces.cpp
+++ b/src/modules/hyprland/workspaces.cpp
@@ -42,6 +42,7 @@ Workspaces::Workspaces(const std::string &id, const Bar &bar, const Json::Value
   if (!id.empty()) {
     m_box.get_style_context()->add_class(id);
   }
+  m_box.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(m_box);
 
   if (!gIPC) {
diff --git a/src/modules/image.cpp b/src/modules/image.cpp
index 3c90b557..8274d323 100644
--- a/src/modules/image.cpp
+++ b/src/modules/image.cpp
@@ -7,6 +7,7 @@ waybar::modules::Image::Image(const std::string& id, const Json::Value& config)
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
 
   dp.emit();
diff --git a/src/modules/keyboard_state.cpp b/src/modules/keyboard_state.cpp
index edab0827..18ce0a7c 100644
--- a/src/modules/keyboard_state.cpp
+++ b/src/modules/keyboard_state.cpp
@@ -132,6 +132,7 @@ waybar::modules::KeyboardState::KeyboardState(const std::string& id, const Bar&
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
 
   if (config_["device-path"].isString()) {
diff --git a/src/modules/river/tags.cpp b/src/modules/river/tags.cpp
index cad8c762..9e7cd5aa 100644
--- a/src/modules/river/tags.cpp
+++ b/src/modules/river/tags.cpp
@@ -111,6 +111,7 @@ Tags::Tags(const std::string &id, const waybar::Bar &bar, const Json::Value &con
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
 
   // Default to 9 tags, cap at 32
diff --git a/src/modules/sni/tray.cpp b/src/modules/sni/tray.cpp
index 8a6a5b82..a2c56808 100644
--- a/src/modules/sni/tray.cpp
+++ b/src/modules/sni/tray.cpp
@@ -15,6 +15,7 @@ Tray::Tray(const std::string& id, const Bar& bar, const Json::Value& config)
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   if (config_["spacing"].isUInt()) {
     box_.set_spacing(config_["spacing"].asUInt());
   }
diff --git a/src/modules/sway/workspaces.cpp b/src/modules/sway/workspaces.cpp
index 37cc7485..c8ec4387 100644
--- a/src/modules/sway/workspaces.cpp
+++ b/src/modules/sway/workspaces.cpp
@@ -37,6 +37,7 @@ Workspaces::Workspaces(const std::string &id, const Bar &bar, const Json::Value
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
   ipc_.subscribe(R"(["workspace"])");
   ipc_.signal_event.connect(sigc::mem_fun(*this, &Workspaces::onEvent));
diff --git a/src/modules/wlr/taskbar.cpp b/src/modules/wlr/taskbar.cpp
index 57f72978..2709584b 100644
--- a/src/modules/wlr/taskbar.cpp
+++ b/src/modules/wlr/taskbar.cpp
@@ -737,6 +737,7 @@ Taskbar::Taskbar(const std::string &id, const waybar::Bar &bar, const Json::Valu
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   box_.get_style_context()->add_class("empty");
   event_box_.add(box_);
 
diff --git a/src/modules/wlr/workspace_manager.cpp b/src/modules/wlr/workspace_manager.cpp
index 17e5bc9c..f556a161 100644
--- a/src/modules/wlr/workspace_manager.cpp
+++ b/src/modules/wlr/workspace_manager.cpp
@@ -52,6 +52,7 @@ WorkspaceManager::WorkspaceManager(const std::string &id, const waybar::Bar &bar
   if (!id.empty()) {
     box_.get_style_context()->add_class(id);
   }
+  box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
 
   add_registry_listener(this);