diff --git a/godot-core/src/deprecated.rs b/godot-core/src/deprecated.rs
index bde072132..00c88f4f8 100644
--- a/godot-core/src/deprecated.rs
+++ b/godot-core/src/deprecated.rs
@@ -37,6 +37,12 @@ pub use crate::emit_deprecated_warning;
 // ----------------------------------------------------------------------------------------------------------------------------------------------
 // Library-side deprecations -- see usage description above.
 
+#[deprecated = "\n\
+    #[class(no_init, base=EditorPlugin)] will crash when opened in the editor.\n\
+    EditorPlugin classes are automatically instantiated by Godot and require a default constructor.\n\
+    Use #[class(init)] instead, or provide a custom init() function in the IEditorPlugin impl."]
+pub const fn class_no_init_editor_plugin() {}
+
 // ----------------------------------------------------------------------------------------------------------------------------------------------
 // Godot-side deprecations (we may mark them deprecated but keep support).
 
diff --git a/godot-macros/src/class/derive_godot_class.rs b/godot-macros/src/class/derive_godot_class.rs
index e2b6533b4..b1696db12 100644
--- a/godot-macros/src/class/derive_godot_class.rs
+++ b/godot-macros/src/class/derive_godot_class.rs
@@ -290,7 +290,7 @@ pub fn make_existence_check(ident: &Ident) -> TokenStream {
 // ----------------------------------------------------------------------------------------------------------------------------------------------
 // Implementation
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Eq, PartialEq)]
 enum InitStrategy {
     Generated,
     UserDefined,
@@ -531,11 +531,12 @@ fn parse_struct_attributes(class: &venial::Struct) -> ParseResult<ClassAttribute
             is_tool = true;
         }
 
-        // Deprecated #[class(editor_plugin)]
-        if let Some(_attr_key) = parser.handle_alone_with_span("editor_plugin")? {
-            deprecations.push(quote_spanned! { _attr_key.span()=>
-                ::godot::__deprecated::emit_deprecated_warning!(class_editor_plugin);
-            });
+        // Removed #[class(editor_plugin)]
+        if let Some(key) = parser.handle_alone_with_span("editor_plugin")? {
+            return bail!(
+                key,
+                "#[class(editor_plugin)] has been removed in favor of #[class(tool, base=EditorPlugin)]",
+            );
         }
 
         // #[class(rename = NewName)]
@@ -556,18 +557,24 @@ fn parse_struct_attributes(class: &venial::Struct) -> ParseResult<ClassAttribute
             }
         }
 
-        // Deprecated #[class(hidden)]
-        if let Some(ident) = parser.handle_alone_with_span("hidden")? {
-            is_internal = true;
-
-            deprecations.push(quote_spanned! { ident.span()=>
-                ::godot::__deprecated::emit_deprecated_warning!(class_hidden);
-            });
+        // Removed #[class(hidden)]
+        if let Some(key) = parser.handle_alone_with_span("hidden")? {
+            return bail!(
+                key,
+                "#[class(hidden)] has been renamed to #[class(internal)]",
+            );
         }
 
         parser.finish()?;
     }
 
+    // Deprecated: #[class(no_init)] with base=EditorPlugin
+    if matches!(init_strategy, InitStrategy::Absent) && base_ty == ident("EditorPlugin") {
+        deprecations.push(quote! {
+            ::godot::__deprecated::emit_deprecated_warning!(class_no_init_editor_plugin);
+        });
+    }
+
     post_validate(&base_ty, is_tool)?;
 
     Ok(ClassAttributes {
@@ -587,6 +594,7 @@ fn parse_fields(
 ) -> ParseResult<Fields> {
     let mut all_fields = vec![];
     let mut base_field = Option::<Field>::None;
+    #[allow(unused_mut)] // Less chore when adding/removing deprecations.
     let mut deprecations = vec![];
     let mut errors = vec![];
 
@@ -633,21 +641,12 @@ fn parse_fields(
                 });
             }
 
-            // Deprecated #[init(default = expr)]
-            if let Some((key, default)) = parser.handle_expr_with_key("default")? {
-                if field.default_val.is_some() {
-                    return bail!(
-                        key,
-                        "Cannot use both `val` and `default` keys in #[init]; prefer using `val`"
-                    );
-                }
-                field.default_val = Some(FieldDefault {
-                    default_val: default,
-                    span: parser.span(),
-                });
-                deprecations.push(quote_spanned! { parser.span()=>
-                    ::godot::__deprecated::emit_deprecated_warning!(init_default);
-                })
+            // Removed #[init(default = ...)]
+            if let Some((key, _default)) = parser.handle_expr_with_key("default")? {
+                return bail!(
+                    key,
+                    "#[init(default = ...)] has been renamed to #[init(val = ...)]",
+                );
             }
 
             // #[init(node = "PATH")]
diff --git a/itest/rust/src/object_tests/virtual_methods_test.rs b/itest/rust/src/object_tests/virtual_methods_test.rs
index 27ea6e5f1..17fd5e610 100644
--- a/itest/rust/src/object_tests/virtual_methods_test.rs
+++ b/itest/rust/src/object_tests/virtual_methods_test.rs
@@ -738,7 +738,7 @@ impl GetSetTest {
 // There isn't a good way to test editor plugins, but we can at least declare one to ensure that the macro
 // compiles.
 #[derive(GodotClass)]
-#[class(no_init, base = EditorPlugin, tool)]
+#[class(init, base = EditorPlugin, tool)]
 struct CustomEditorPlugin;
 
 // Just override EditorPlugin::edit() to verify method is declared with Option<T>.