diff --git a/crates/get-size2/Cargo.toml b/crates/get-size2/Cargo.toml
index 0cebd46..fe4fa14 100644
--- a/crates/get-size2/Cargo.toml
+++ b/crates/get-size2/Cargo.toml
@@ -23,6 +23,7 @@ chrono-tz = { version = "0.10", default-features = false, optional = true }
 compact_str = { version = "0.9", default-features = false, optional = true }
 hashbrown = { version = "0.16", default-features = false, optional = true }
 indexmap = { version = "2.10", default-features = false, optional = true }
+ordermap = { version = "1.0", default-features = false, optional = true }
 smallvec = { version = "1", default-features = false, optional = true }
 thin-vec = { version = "0.2", default-features = false, optional = true }
 url = { version = "2", default-features = false, optional = true }
@@ -36,6 +37,7 @@ get-size2 = { path = ".", features = [
     "compact-str",
     "hashbrown",
     "indexmap",
+    "ordermap",
     "smallvec",
     "thin-vec",
     "url",
@@ -51,6 +53,7 @@ chrono-tz = ["dep:chrono-tz"]
 compact-str = ["dep:compact_str"]
 hashbrown = ["dep:hashbrown"]
 indexmap = ["dep:indexmap"]
+ordermap = ["dep:ordermap"]
 smallvec = ["dep:smallvec"]
 thin-vec = ["dep:thin-vec"]
 url = ["dep:url"]
diff --git a/crates/get-size2/src/lib.rs b/crates/get-size2/src/lib.rs
index 752ae38..7b5deb6 100644
--- a/crates/get-size2/src/lib.rs
+++ b/crates/get-size2/src/lib.rs
@@ -813,3 +813,40 @@ where
         (size + allocation_size, tracker)
     }
 }
+
+#[cfg(feature = "ordermap")]
+impl<K, V, S> GetSize for ordermap::OrderMap<K, V, S>
+where
+    K: GetSize,
+    V: GetSize,
+    S: std::hash::BuildHasher,
+{
+    fn get_heap_size_with_tracker<Tr: GetSizeTracker>(&self, tracker: Tr) -> (usize, Tr) {
+        let (size, tracker) = self
+            .iter()
+            .fold((0, tracker), |(size, tracker), (key, value)| {
+                let (key_size, tracker) = K::get_heap_size_with_tracker(key, tracker);
+                let (value_size, tracker) = V::get_heap_size_with_tracker(value, tracker);
+                (size + key_size + value_size, tracker)
+            });
+
+        let allocation_size = self.capacity() * <(K, V)>::get_stack_size();
+        (size + allocation_size, tracker)
+    }
+}
+
+#[cfg(feature = "ordermap")]
+impl<T, S> GetSize for ordermap::OrderSet<T, S>
+where
+    T: GetSize,
+{
+    fn get_heap_size_with_tracker<Tr: GetSizeTracker>(&self, tracker: Tr) -> (usize, Tr) {
+        let (size, tracker) = self.iter().fold((0, tracker), |(size, tracker), element| {
+            let (elem_size, tracker) = T::get_heap_size_with_tracker(element, tracker);
+            (size + elem_size, tracker)
+        });
+
+        let allocation_size = self.capacity() * T::get_stack_size();
+        (size + allocation_size, tracker)
+    }
+}
diff --git a/crates/get-size2/src/test.rs b/crates/get-size2/src/test.rs
index 5d5b5a9..bc873a9 100644
--- a/crates/get-size2/src/test.rs
+++ b/crates/get-size2/src/test.rs
@@ -541,6 +541,30 @@ fn test_indexmap() {
     assert!(set.get_heap_size() >= size_of::<String>() + VALUE_STR.len());
 }
 
+#[test]
+fn test_ordermap() {
+    use std::hash::RandomState;
+
+    const VALUE_STR: &str = "A very looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooonng string.";
+
+    let hasher = RandomState::new();
+
+    let mut map = ordermap::OrderMap::with_capacity_and_hasher(1, hasher);
+    assert_eq!(map.get_heap_size(), 40);
+    map.insert(VALUE_STR, String::from(VALUE_STR));
+    assert!(map.get_heap_size() >= size_of::<(&'static str, String)>() + VALUE_STR.len());
+
+    let mut map = ordermap::OrderMap::<i32, String, RandomState>::default();
+    assert_eq!(map.get_heap_size(), 0);
+    map.insert(0, String::from(VALUE_STR));
+    assert!(map.get_heap_size() >= size_of::<(i32, String)>() + VALUE_STR.len());
+
+    let mut set = ordermap::OrderSet::<String, RandomState>::default();
+    assert_eq!(set.get_heap_size(), 0);
+    set.insert(String::from(VALUE_STR));
+    assert!(set.get_heap_size() >= size_of::<String>() + VALUE_STR.len());
+}
+
 #[test]
 fn refcell() {
     // Test RefCell with a simple type