diff --git a/beacon_chain/attestation_validation/src/enums.rs b/beacon_chain/attestation_validation/src/enums.rs
index 3174d1154..6c94c628c 100644
--- a/beacon_chain/attestation_validation/src/enums.rs
+++ b/beacon_chain/attestation_validation/src/enums.rs
@@ -1,4 +1,5 @@
 /// Reasons why an `AttestationRecord` can be invalid.
+#[derive(PartialEq, Debug)]
 pub enum Invalid {
     AttestationTooRecent,
     AttestationTooOld,
@@ -14,6 +15,7 @@ pub enum Invalid {
 ///
 /// Distinct from the `Error` enum as an `Outcome` indicates that validation executed sucessfully
 /// and determined the validity `AttestationRecord`.
+#[derive(PartialEq, Debug)]
 pub enum Outcome {
     Valid,
     Invalid(Invalid),
@@ -23,6 +25,7 @@ pub enum Outcome {
 ///
 /// Distinct from the `Outcome` enum as `Errors` indicate that validation encountered an unexpected
 /// condition and was unable to perform its duty.
+#[derive(PartialEq, Debug)]
 pub enum Error {
     BlockHasNoParent,
     BadValidatorIndex,
diff --git a/beacon_chain/attestation_validation/src/validate_signature.rs b/beacon_chain/attestation_validation/src/validate_signature.rs
index 67ba7d2ec..050f9cdf9 100644
--- a/beacon_chain/attestation_validation/src/validate_signature.rs
+++ b/beacon_chain/attestation_validation/src/validate_signature.rs
@@ -62,3 +62,88 @@ impl From<BitfieldError> for Error {
         Error::OutOfBoundsBitfieldIndex
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::super::bls::{Keypair, Signature};
+    use super::super::db::MemoryDB;
+    use super::*;
+    use std::sync::Arc;
+
+    /*
+     * TODO: Test cases are not comprehensive.
+     * https://github.com/sigp/lighthouse/issues/94
+     */
+
+    #[test]
+    fn test_signature_verification() {
+        let attestation_data = AttestationData::zero();
+        let message = attestation_data_signing_message(&attestation_data);
+        let signing_keypairs = vec![
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+        ];
+        let non_signing_keypairs = vec![
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+            Keypair::random(),
+        ];
+        /*
+         * Signing keypairs first, then non-signing
+         */
+        let mut all_keypairs = signing_keypairs.clone();
+        all_keypairs.append(&mut non_signing_keypairs.clone());
+
+        let attestation_indices: Vec<usize> = (0..all_keypairs.len()).collect();
+        let mut bitfield = Bitfield::from_elem(all_keypairs.len(), false);
+        for i in 0..signing_keypairs.len() {
+            bitfield.set(i, true).unwrap();
+        }
+
+        let db = Arc::new(MemoryDB::open());
+        let store = ValidatorStore::new(db);
+
+        for (i, keypair) in all_keypairs.iter().enumerate() {
+            store.put_public_key_by_index(i, &keypair.pk).unwrap();
+        }
+
+        let mut agg_sig = AggregateSignature::new();
+        for keypair in &signing_keypairs {
+            let sig = Signature::new(&message, &keypair.sk);
+            agg_sig.add(&sig);
+        }
+
+        /*
+         * Test using all valid parameters.
+         */
+        let outcome = validate_attestation_signature(
+            &attestation_data,
+            &bitfield,
+            &agg_sig,
+            &attestation_indices,
+            &store,
+        ).unwrap();
+        assert_eq!(outcome, Outcome::Valid);
+
+        /*
+         * Add another validator to the bitfield, run validation will all other
+         * parameters the same and assert that it fails.
+         */
+        bitfield.set(signing_keypairs.len() + 1, true).unwrap();
+        let outcome = validate_attestation_signature(
+            &attestation_data,
+            &bitfield,
+            &agg_sig,
+            &attestation_indices,
+            &store,
+        ).unwrap();
+        assert_eq!(outcome, Outcome::Invalid(Invalid::SignatureInvalid));
+    }
+}