diff --git a/beacon-chain/operations/slashings/service_attester_test.go b/beacon-chain/operations/slashings/service_attester_test.go
index 06ac806dfe91..3abd20cf10df 100644
--- a/beacon-chain/operations/slashings/service_attester_test.go
+++ b/beacon-chain/operations/slashings/service_attester_test.go
@@ -314,9 +314,7 @@ func TestPool_InsertAttesterSlashing_SigFailsVerify_ClearPool(t *testing.T) {
 	// We mess up the signature of the second slashing.
 	badSig := make([]byte, 96)
 	copy(badSig, "muahaha")
-	pending, ok := pendingSlashings[1].attesterSlashing.(*ethpb.AttesterSlashing)
-	require.Equal(t, true, ok, "unexpected type of attester slashing")
-	pending.Attestation_1.Signature = badSig
+	pendingSlashings[1].attesterSlashing.(*ethpb.AttesterSlashing).Attestation_1.Signature = badSig
 	slashings[1].Attestation_1.Signature = badSig
 	p := &Pool{
 		pendingAttesterSlashing: make([]*PendingAttesterSlashing, 0),
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_test.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_test.go
index 40fb8751a773..796cdf1d1af3 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_test.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_test.go
@@ -2447,9 +2447,7 @@ func TestProposer_FilterAttestation(t *testing.T) {
 					require.NoError(t, err)
 					sigs := make([]bls.Signature, len(attestingIndices))
 					var zeroSig [96]byte
-					att, ok := atts[i].(*ethpb.Attestation)
-					require.Equal(t, true, ok, "unexpected type of attestation")
-					att.Signature = zeroSig[:]
+					atts[i].(*ethpb.Attestation).Signature = zeroSig[:]
 
 					for i, indice := range attestingIndices {
 						hashTreeRoot, err := signing.ComputeSigningRoot(atts[i].GetData(), domain)
@@ -2457,7 +2455,7 @@ func TestProposer_FilterAttestation(t *testing.T) {
 						sig := privKeys[indice].Sign(hashTreeRoot[:])
 						sigs[i] = sig
 					}
-					att.Signature = bls.AggregateSignatures(sigs).Marshal()
+					atts[i].(*ethpb.Attestation).Signature = bls.AggregateSignatures(sigs).Marshal()
 				}
 				return atts
 			},
diff --git a/beacon-chain/slasher/detect_attestations_test.go b/beacon-chain/slasher/detect_attestations_test.go
index a8e8aae333ed..0026f36877fc 100644
--- a/beacon-chain/slasher/detect_attestations_test.go
+++ b/beacon-chain/slasher/detect_attestations_test.go
@@ -667,13 +667,9 @@ func Test_processAttestations(t *testing.T) {
 					)
 
 					// Create the attester slashing.
-					att_1, ok := wrapper_1.IndexedAttestation.(*ethpb.IndexedAttestation)
-					require.Equal(t, true, ok, "unexpected type of first attestation")
-					att_2, ok := wrapper_2.IndexedAttestation.(*ethpb.IndexedAttestation)
-					require.Equal(t, true, ok, "unexpected type of second attestation")
 					expectedSlashing := &ethpb.AttesterSlashing{
-						Attestation_1: att_1,
-						Attestation_2: att_2,
+						Attestation_1: wrapper_1.IndexedAttestation.(*ethpb.IndexedAttestation),
+						Attestation_2: wrapper_2.IndexedAttestation.(*ethpb.IndexedAttestation),
 					}
 
 					root, err := expectedSlashing.HashTreeRoot()
@@ -1168,9 +1164,7 @@ func Test_applyAttestationForValidator_MinSpanChunk(t *testing.T) {
 	)
 	require.NoError(t, err)
 	require.IsNil(t, slashing)
-	indexedAtt, ok := att.IndexedAttestation.(*ethpb.IndexedAttestation)
-	require.Equal(t, true, ok, "unexpected type of indexed attestation")
-	indexedAtt.AttestingIndices = []uint64{uint64(validatorIdx)}
+	att.IndexedAttestation.(*ethpb.IndexedAttestation).AttestingIndices = []uint64{uint64(validatorIdx)}
 	err = slasherDB.SaveAttestationRecordsForValidators(
 		ctx,
 		[]*slashertypes.IndexedAttestationWrapper{att},
@@ -1227,9 +1221,7 @@ func Test_applyAttestationForValidator_MaxSpanChunk(t *testing.T) {
 	)
 	require.NoError(t, err)
 	require.Equal(t, true, slashing == nil)
-	indexedAtt, ok := att.IndexedAttestation.(*ethpb.IndexedAttestation)
-	require.Equal(t, true, ok, "unexpected type of indexed attestation")
-	indexedAtt.AttestingIndices = []uint64{uint64(validatorIdx)}
+	att.IndexedAttestation.(*ethpb.IndexedAttestation).AttestingIndices = []uint64{uint64(validatorIdx)}
 	err = slasherDB.SaveAttestationRecordsForValidators(
 		ctx,
 		[]*slashertypes.IndexedAttestationWrapper{att},