diff --git a/01.workspace/heave/src/imp/catalog_for_each_mut.rs b/01.workspace/heave/src/imp/catalog_for_each_mut.rs
new file mode 100644
index 0000000..e0eb48c
--- /dev/null
+++ b/01.workspace/heave/src/imp/catalog_for_each_mut.rs
@@ -0,0 +1,23 @@
+use crate::*;
+
+impl Catalog {
+    pub fn for_each_mut<T, F>(&self, predicate: F) -> Result<(), FailedTo>
+    where
+        T: EAV,
+        F: Fn(&mut T) -> (),
+    {
+        self.on_items(|items| {
+            for entity in items.values_mut() {
+                let original_item =
+                    T::try_from(entity.clone()).map_err(|_| FailedTo::ConvertEntity)?;
+                let mut item = T::try_from(entity.clone()).map_err(|_| FailedTo::ConvertEntity)?;
+                predicate(&mut item);
+                if item != original_item {
+                    *entity = T::try_into(item).map_err(|_| FailedTo::ConvertObject)?;
+                    entity.state = EntityState::Updated;
+                }
+            }
+            Ok(())
+        })
+    }
+}
diff --git a/01.workspace/heave/src/imp/mod.rs b/01.workspace/heave/src/imp/mod.rs
index 9c43247..b3bf8bf 100644
--- a/01.workspace/heave/src/imp/mod.rs
+++ b/01.workspace/heave/src/imp/mod.rs
@@ -2,6 +2,7 @@ pub mod bool_try_from_value;
 pub mod catalog_contains_key;
 pub mod catalog_delete;
 pub mod catalog_for_each;
+pub mod catalog_for_each_mut;
 pub mod catalog_get;
 pub mod catalog_get_by;
 pub mod catalog_init;