diff --git a/testutil/mock/privval.go b/testutil/mock/privval.go
index 6aaceedd2e34..9c5a745d1b55 100644
--- a/testutil/mock/privval.go
+++ b/testutil/mock/privval.go
@@ -14,7 +14,7 @@ import (
 
 var _ tmtypes.PrivValidator = PV{}
 
-// MockPV implements PrivValidator without any safety or persistence.
+// PV implements PrivValidator without any safety or persistence.
 // Only use it for testing.
 type PV struct {
 	PrivKey cryptotypes.PrivKey
diff --git a/testutil/mock/privval_test.go b/testutil/mock/privval_test.go
new file mode 100644
index 000000000000..a3326dbe4a09
--- /dev/null
+++ b/testutil/mock/privval_test.go
@@ -0,0 +1,32 @@
+package mock
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
+)
+
+func TestGetPubKey(t *testing.T) {
+	pv := NewPV()
+	pb, err := pv.GetPubKey(context.Background())
+	require.NoError(t, err)
+	require.NotNil(t, pb)
+}
+
+func TestSignVote(t *testing.T) {
+	pv := NewPV()
+	v := tmproto.Vote{}
+	err := pv.SignVote(context.Background(), "chain-id", &v)
+	require.NoError(t, err)
+	require.NotNil(t, v.Signature)
+}
+
+func TestSignProposal(t *testing.T) {
+	pv := NewPV()
+	p := tmproto.Proposal{}
+	err := pv.SignProposal(context.Background(), "chain-id", &p)
+	require.NoError(t, err)
+	require.NotNil(t, p.Signature)
+}
diff --git a/testutil/network/network.go b/testutil/network/network.go
index 995eb56889df..2d89c4e69e9c 100644
--- a/testutil/network/network.go
+++ b/testutil/network/network.go
@@ -181,18 +181,22 @@ type Logger interface {
 var _ Logger = (*testing.T)(nil)
 var _ Logger = (*CLILogger)(nil)
 
+// CLILogger wraps a cobra.Command and provides command logging methods.
 type CLILogger struct {
 	cmd *cobra.Command
 }
 
+// Log logs given args.
 func (s CLILogger) Log(args ...interface{}) {
 	s.cmd.Println(args...)
 }
 
+// Logf logs given args according to a format specifier.
 func (s CLILogger) Logf(format string, args ...interface{}) {
 	s.cmd.Printf(format, args...)
 }
 
+// NewCLILogger creates a new CLILogger.
 func NewCLILogger(cmd *cobra.Command) CLILogger {
 	return CLILogger{cmd}
 }
diff --git a/testutil/network/util.go b/testutil/network/util.go
index 6e5d2865c725..79777ed09881 100644
--- a/testutil/network/util.go
+++ b/testutil/network/util.go
@@ -2,6 +2,7 @@ package network
 
 import (
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"path/filepath"
 	"time"
@@ -16,6 +17,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/server/api"
 	servergrpc "github.com/cosmos/cosmos-sdk/server/grpc"
 	srvtypes "github.com/cosmos/cosmos-sdk/server/types"
+	"github.com/cosmos/cosmos-sdk/types/errors"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	"github.com/cosmos/cosmos-sdk/x/genutil"
@@ -55,11 +57,11 @@ func startInProcess(cfg Config, val *Validator) error {
 	if val.RPCAddress != "" {
 		node, ok := val.tmNode.(local.NodeService)
 		if !ok {
-			panic("can't cast service.Service to NodeService")
+			return fmt.Errorf("failed to cast %T to NodeService", val.tmNode)
 		}
 		val.RPCClient, err = local.New(node)
 		if err != nil {
-			panic("cant create a local node")
+			return errors.Wrap(err, "failed to create a local node")
 		}
 	}