diff --git a/eth2/utils/ssz/Cargo.toml b/eth2/utils/ssz/Cargo.toml
index ecefd69fe..dda169006 100644
--- a/eth2/utils/ssz/Cargo.toml
+++ b/eth2/utils/ssz/Cargo.toml
@@ -4,6 +4,9 @@ version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
 
+[dev-dependencies]
+ssz_derive = { path = "../ssz_derive" }
+
 [dependencies]
 bytes = "0.4.9"
 ethereum-types = "0.5"
diff --git a/eth2/utils/ssz/tests/tests.rs b/eth2/utils/ssz/tests/tests.rs
index 3950c94c6..3850e871e 100644
--- a/eth2/utils/ssz/tests/tests.rs
+++ b/eth2/utils/ssz/tests/tests.rs
@@ -1,29 +1,133 @@
 use ssz::{Decodable, Encodable};
+use ssz_derive::Encode;
 
-fn round_trip<T: Encodable + Decodable + std::fmt::Debug + PartialEq>(item: T) {
-    let encoded = &item.as_ssz_bytes();
-    dbg!(encoded);
-    assert_eq!(T::from_ssz_bytes(&encoded), Ok(item));
+fn round_trip<T: Encodable + Decodable + std::fmt::Debug + PartialEq>(items: Vec<T>) {
+    for item in items {
+        let encoded = &item.as_ssz_bytes();
+        dbg!(encoded);
+        assert_eq!(T::from_ssz_bytes(&encoded), Ok(item));
+    }
 }
 
 #[test]
 fn vec_u16_round_trip() {
-    round_trip::<Vec<u16>>(vec![]);
-    round_trip::<Vec<u16>>(vec![255]);
-    round_trip::<Vec<u16>>(vec![0, 1, 2]);
-    round_trip::<Vec<u16>>(vec![100; 64]);
+    let items: Vec<Vec<u16>> = vec![
+        vec![],
+        vec![255],
+        vec![0, 1, 2],
+        vec![100; 64],
+        vec![255, 0, 255],
+    ];
+
+    round_trip(items);
 }
 
 #[test]
 fn vec_of_vec_u16_round_trip() {
-    round_trip::<Vec<Vec<u16>>>(vec![]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![1, 2, 3]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![], vec![]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![], vec![1, 2, 3]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![1, 2, 3], vec![1, 2, 3]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![1, 2, 3], vec![], vec![1, 2, 3]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![], vec![], vec![1, 2, 3]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![], vec![1], vec![1, 2, 3]]);
-    round_trip::<Vec<Vec<u16>>>(vec![vec![], vec![1], vec![1, 2, 3]]);
+    let items: Vec<Vec<Vec<u16>>> = vec![
+        vec![],
+        vec![vec![]],
+        vec![vec![1, 2, 3]],
+        vec![vec![], vec![]],
+        vec![vec![], vec![1, 2, 3]],
+        vec![vec![1, 2, 3], vec![1, 2, 3]],
+        vec![vec![1, 2, 3], vec![], vec![1, 2, 3]],
+        vec![vec![], vec![], vec![1, 2, 3]],
+        vec![vec![], vec![1], vec![1, 2, 3]],
+        vec![vec![], vec![1], vec![1, 2, 3]],
+    ];
+
+    round_trip(items);
 }
+
+#[derive(Debug, PartialEq, Encode)]
+struct FixedLen {
+    a: u16,
+    b: u64,
+    c: u32,
+}
+
+#[test]
+fn fixed_len_struct_encoding() {
+    let items: Vec<FixedLen> = vec![
+        FixedLen { a: 0, b: 0, c: 0 },
+        FixedLen { a: 1, b: 1, c: 1 },
+        FixedLen { a: 1, b: 0, c: 1 },
+    ];
+
+    let expected_encodings = vec![
+        //  | u16--| u64----------------------------| u32----------|
+        vec![00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00],
+        vec![01, 00, 01, 00, 00, 00, 00, 00, 00, 00, 01, 00, 00, 00],
+        vec![01, 00, 00, 00, 00, 00, 00, 00, 00, 00, 01, 00, 00, 00],
+    ];
+
+    for i in 0..items.len() {
+        assert_eq!(
+            items[i].as_ssz_bytes(),
+            expected_encodings[i],
+            "Failed on {}",
+            i
+        );
+    }
+}
+
+#[derive(Debug, PartialEq, Encode)]
+struct VariableLen {
+    a: u16,
+    b: Vec<u16>,
+    c: u32,
+}
+
+#[test]
+fn variable_len_struct_encoding() {
+    let items: Vec<VariableLen> = vec![
+        VariableLen {
+            a: 0,
+            b: vec![],
+            c: 0,
+        },
+        VariableLen {
+            a: 1,
+            b: vec![0],
+            c: 1,
+        },
+        VariableLen {
+            a: 1,
+            b: vec![0, 1, 2],
+            c: 1,
+        },
+    ];
+
+    let expected_encodings = vec![
+        //   00..................................09
+        //  | u16--| vec offset-----| u32------------| vec payload --------|
+        vec![00, 00, 10, 00, 00, 00, 00, 00, 00, 00],
+        vec![01, 00, 10, 00, 00, 00, 01, 00, 00, 00, 00, 00],
+        vec![
+            01, 00, 10, 00, 00, 00, 01, 00, 00, 00, 00, 00, 01, 00, 02, 00,
+        ],
+    ];
+
+    for i in 0..items.len() {
+        assert_eq!(
+            items[i].as_ssz_bytes(),
+            expected_encodings[i],
+            "Failed on {}",
+            i
+        );
+    }
+}
+
+/*
+#[test]
+fn vec_of_fixed_len_struct() {
+    let items: Vec<FixedLen> = vec![
+        FixedLen { a: 0, b: 0, c: 0 },
+        FixedLen { a: 1, b: 1, c: 1 },
+        FixedLen { a: 1, b: 0, c: 1 },
+    ];
+
+    round_trip(items);
+}
+*/