diff --git a/src/trie/trie_impl.rs b/src/trie/trie_impl.rs
index facb37a..42ed460 100644
--- a/src/trie/trie_impl.rs
+++ b/src/trie/trie_impl.rs
@@ -243,6 +243,44 @@ mod search_tests {
         let _ = trie.common_prefix_search::<String, _>("").next();
     }
 
+
+    #[cfg(feature = "mem_dbg")]
+    #[test]
+    /// ```sh
+    /// cargo test --features mem_dbg memsize -- --nocapture
+    /// ```
+    fn memsize() {
+        use std::{env, io::{BufReader, BufRead}, fs::{File}};
+        use mem_dbg::*;
+
+        const COUNT: usize = 100;
+        let mut builder = TrieBuilder::new();
+
+        let repo_root = env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR environment variable must be set.");
+        let edict2_path = format!("{}/benches/edict.furigana", repo_root);
+        println!("Reading dictionary file from: {}", edict2_path);
+
+        let mut n_words = 0;
+        let mut accum = 0;
+        for result in BufReader::new(File::open(edict2_path).unwrap()).lines().take(COUNT) {
+            let l = result.unwrap();
+            accum += l.len();
+            builder.push(l);
+            n_words += 1;
+        }
+        println!("Read {} words, {} bytes.", n_words, accum);
+
+        let trie = builder.build();
+        let trie_size = trie.mem_size(SizeFlags::default());
+        eprintln!("Trie size {trie_size}");
+        let uncompressed: Vec<String> = trie.iter().collect();
+        let uncompressed_size = uncompressed.mem_size(SizeFlags::default());
+        eprintln!("Uncompressed size {}", uncompressed_size);
+        assert!(accum < trie_size); // This seems wrong to me.
+        assert!(trie_size < uncompressed_size);
+
+    }
+
     mod exact_match_tests {
         macro_rules! parameterized_tests {
             ($($name:ident: $value:expr,)*) => {