diff --git a/twust-macro/src/config/classes.rs b/twust-macro/src/config/classes.rs
index 01effdf..1556eca 100644
--- a/twust-macro/src/config/classes.rs
+++ b/twust-macro/src/config/classes.rs
@@ -516,6 +516,24 @@ define_tailwind_field!({
     variants: []
 });
 
+// 3. Placeholder
+// Placeholder Color
+// Placeholder Opacity
+define_tailwind_color_field!({
+    name: PlaceholderColor,
+    prefix: "placeholder-color",
+    field_name: placeholder_color,
+    variants: []
+});
+
+define_tailwind_field!({
+    name: PlaceholderOpacity,
+    prefix: "placeholder-opacity",
+    inherited: placeholder_opacity,
+    field_name: placeholder_opacity,
+    variants: []
+});
+
 // 3. Spacing
 // Padding
 // Margin
diff --git a/twust-macro/src/config/mod.rs b/twust-macro/src/config/mod.rs
index 54a4f91..5b3c9a4 100644
--- a/twust-macro/src/config/mod.rs
+++ b/twust-macro/src/config/mod.rs
@@ -86,7 +86,7 @@ pub fn get_classes(config: &TailwindConfig) -> Vec<String> {
     // by the user.
 
     let mut classes = Vec::new();
-    let utilities: [Box<dyn TailwindField>; 175] = [
+    let utilities: [Box<dyn TailwindField>; 177] = [
         Box::new(AspectRatio),
         Box::new(Container),
         Box::new(Columns),
@@ -143,6 +143,8 @@ pub fn get_classes(config: &TailwindConfig) -> Vec<String> {
         Box::new(PlaceContent),
         Box::new(PlaceItems),
         Box::new(PlaceSelf),
+        Box::new(PlaceholderColor),
+        Box::new(PlaceholderOpacity),
         Box::new(Padding),
         Box::new(Margin),
         Box::new(SpaceBetween),
diff --git a/twust-macro/src/tailwind/default_classnames.rs b/twust-macro/src/tailwind/default_classnames.rs
index 193e5ae..52fdafb 100644
--- a/twust-macro/src/tailwind/default_classnames.rs
+++ b/twust-macro/src/tailwind/default_classnames.rs
@@ -7,6 +7,7 @@
 // placescreen_readers-shown
 // placeholder-slate-400
 
+#[allow(dead_code)]
 #[derive(Debug, Clone, Copy)]
 pub struct TailWindCssDefaultClassNames {
     pub aspect_ratio: [&'static str; 3],