diff --git a/crawler/crawl.go b/crawler/crawl.go
index b06073e41..a62bd6778 100644
--- a/crawler/crawl.go
+++ b/crawler/crawl.go
@@ -181,7 +181,7 @@ func (c *Crawler) readLoop(node *Node) {
 }
 
 func (c *Crawler) consumeMessage(eventMsg ctypes.ResultEvent, node *Node) error {
-	block := eventMsg.Data.(*types.Block)
+	block := eventMsg.Data.(*types.EventDataNewBlock).Block
 	node.LastSeen = time.Now()
 	node.BlockHeight = block.Height
 	node.BlockHistory[block.Height] = node.LastSeen
diff --git a/events/event_cache.go b/events/event_cache.go
index 9f4f08044..d0109ae11 100644
--- a/events/event_cache.go
+++ b/events/event_cache.go
@@ -30,7 +30,7 @@ type eventInfo struct {
 }
 
 // Cache an event to be fired upon finality.
-func (evc *EventCache) FireEvent(event string, data interface{}) {
+func (evc *EventCache) FireEvent(event string, data types.EventData) {
 	// append to list
 	evc.events = append(evc.events, eventInfo{event, data})
 }
diff --git a/events/events.go b/events/events.go
index 25fc7b335..818b1f4f1 100644
--- a/events/events.go
+++ b/events/events.go
@@ -4,6 +4,7 @@ import (
 	"sync"
 
 	. "github.com/tendermint/tendermint/common"
+	"github.com/tendermint/tendermint/types"
 )
 
 // reactors and other modules should export
@@ -14,7 +15,7 @@ type Eventable interface {
 
 // an event switch or cache implements fireable
 type Fireable interface {
-	FireEvent(event string, msg interface{})
+	FireEvent(event string, data types.EventData)
 }
 
 type EventSwitch struct {
@@ -108,7 +109,7 @@ func (evsw *EventSwitch) RemoveListenerForEvent(event string, listenerId string)
 	}
 }
 
-func (evsw *EventSwitch) FireEvent(event string, msg interface{}) {
+func (evsw *EventSwitch) FireEvent(event string, data types.EventData) {
 	// Get the eventCell
 	evsw.mtx.RLock()
 	eventCell := evsw.eventCells[event]
@@ -119,7 +120,7 @@ func (evsw *EventSwitch) FireEvent(event string, msg interface{}) {
 	}
 
 	// Fire event for all listeners in eventCell
-	eventCell.FireEvent(msg)
+	eventCell.FireEvent(data)
 }
 
 //-----------------------------------------------------------------------------
@@ -150,17 +151,17 @@ func (cell *eventCell) RemoveListener(listenerId string) int {
 	return numListeners
 }
 
-func (cell *eventCell) FireEvent(msg interface{}) {
+func (cell *eventCell) FireEvent(data types.EventData) {
 	cell.mtx.RLock()
 	for _, listener := range cell.listeners {
-		listener(msg)
+		listener(data)
 	}
 	cell.mtx.RUnlock()
 }
 
 //-----------------------------------------------------------------------------
 
-type eventCallback func(msg interface{})
+type eventCallback func(data types.EventData)
 
 type eventListener struct {
 	id string
diff --git a/rpc/server/handlers.go b/rpc/server/handlers.go
index 4ba885e19..e66574b1d 100644
--- a/rpc/server/handlers.go
+++ b/rpc/server/handlers.go
@@ -16,6 +16,7 @@ import (
 	"github.com/tendermint/tendermint/events"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	. "github.com/tendermint/tendermint/rpc/types"
+	"github.com/tendermint/tendermint/types"
 	"github.com/tendermint/tendermint/wire"
 )
 
@@ -54,22 +55,22 @@ func NewRPCFunc(f interface{}, args []string) *RPCFunc {
 func funcArgTypes(f interface{}) []reflect.Type {
 	t := reflect.TypeOf(f)
 	n := t.NumIn()
-	types := make([]reflect.Type, n)
+	typez := make([]reflect.Type, n)
 	for i := 0; i < n; i++ {
-		types[i] = t.In(i)
+		typez[i] = t.In(i)
 	}
-	return types
+	return typez
 }
 
 // return a function's return types
 func funcReturnTypes(f interface{}) []reflect.Type {
 	t := reflect.TypeOf(f)
 	n := t.NumOut()
-	types := make([]reflect.Type, n)
+	typez := make([]reflect.Type, n)
 	for i := 0; i < n; i++ {
-		types[i] = t.Out(i)
+		typez[i] = t.Out(i)
 	}
-	return types
+	return typez
 }
 
 // function introspection
@@ -337,7 +338,7 @@ func (wsc *WSConnection) readRoutine() {
 					continue
 				} else {
 					log.Notice("Subscribe to event", "id", wsc.id, "event", event)
-					wsc.evsw.AddListenerForEvent(wsc.id, event, func(msg interface{}) {
+					wsc.evsw.AddListenerForEvent(wsc.id, event, func(msg types.EventData) {
 						// NOTE: RPCResponses of subscribed events have id suffix "#event"
 						wsc.writeRPCResponse(NewRPCResponse(request.Id+"#event", ctypes.ResultEvent{event, msg}, ""))
 					})
diff --git a/rpc/test/ws_helpers.go b/rpc/test/ws_helpers.go
index 9ba5c1f23..3733c8f33 100644
--- a/rpc/test/ws_helpers.go
+++ b/rpc/test/ws_helpers.go
@@ -82,7 +82,8 @@ func waitForEvent(t *testing.T, con *websocket.Conn, eventid string, dieOnTimeou
 					errCh <- err
 					break
 				}
-				if response.Result.(*ctypes.ResultEvent).Event == eventid {
+				event, ok := response.Result.(*ctypes.ResultEvent)
+				if ok && event.Event == eventid {
 					goodCh <- p
 					break
 				}
@@ -109,8 +110,8 @@ func waitForEvent(t *testing.T, con *websocket.Conn, eventid string, dieOnTimeou
 			// run the check
 			err := check(eventid, p)
 			if err != nil {
-				panic(err)
 				t.Fatal(err)
+				panic(err) // Show the stack trace.
 			}
 		} else {
 			con.Close()
@@ -118,6 +119,7 @@ func waitForEvent(t *testing.T, con *websocket.Conn, eventid string, dieOnTimeou
 		}
 	case err := <-errCh:
 		t.Fatal(err)
+		panic(err) // Show the stack trace.
 	}
 }
 
@@ -140,15 +142,7 @@ func unmarshalResponseNewBlock(b []byte) (*types.Block, error) {
 
 func unmarshalResponseNameReg(b []byte) (*types.NameTx, error) {
 	// unmarshall and assert somethings
-	var response struct {
-		JSONRPC string `json:"jsonrpc"`
-		Id      string `json:"id"`
-		Result  struct {
-			Event string        `json:"event"`
-			Data  *types.NameTx `json:"data"`
-		} `json:"result"`
-		Error string `json:"error"`
-	}
+	var response ctypes.Response
 	var err error
 	wire.ReadJSON(&response, b, &err)
 	if err != nil {
@@ -157,7 +151,7 @@ func unmarshalResponseNameReg(b []byte) (*types.NameTx, error) {
 	if response.Error != "" {
 		return nil, fmt.Errorf(response.Error)
 	}
-	tx := response.Result.Data
+	tx := response.Result.(*ctypes.ResultEvent).Data.(types.EventDataTx).Tx.(*types.NameTx)
 	return tx, nil
 }
 
diff --git a/rpc/types/types.go b/rpc/types/types.go
index 4f7ee208c..c2bd6f5fe 100644
--- a/rpc/types/types.go
+++ b/rpc/types/types.go
@@ -15,9 +15,6 @@ type RPCResponse struct {
 }
 
 func NewRPCResponse(id string, res interface{}, err string) RPCResponse {
-	if res == nil {
-		res = struct{}{}
-	}
 	return RPCResponse{
 		JSONRPC: "2.0",
 		Id:      id,
diff --git a/state/execution.go b/state/execution.go
index b14b8d3c5..92e47b20b 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -628,8 +628,8 @@ func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireab
 		// TODO: maybe we want to take funds on error and allow txs in that don't do anythingi?
 
 		if evc != nil {
-			evc.FireEvent(types.EventStringAccInput(tx.Input.Address), tx)
-			evc.FireEvent(types.EventStringNameReg(tx.Name), tx)
+			evc.FireEvent(types.EventStringAccInput(tx.Input.Address), types.EventDataTx{tx, nil, ""})
+			evc.FireEvent(types.EventStringNameReg(tx.Name), types.EventDataTx{tx, nil, ""})
 		}
 
 		return nil
@@ -711,7 +711,7 @@ func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireab
 		}
 		if evc != nil {
 			// TODO: fire for all inputs
-			evc.FireEvent(types.EventStringBond(), tx)
+			evc.FireEvent(types.EventStringBond(), types.EventDataTx{tx, nil, ""})
 		}
 		return nil
 
@@ -736,7 +736,7 @@ func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireab
 		// Good!
 		_s.unbondValidator(val)
 		if evc != nil {
-			evc.FireEvent(types.EventStringUnbond(), tx)
+			evc.FireEvent(types.EventStringUnbond(), types.EventDataTx{tx, nil, ""})
 		}
 		return nil
 
@@ -764,7 +764,7 @@ func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireab
 		// Good!
 		_s.rebondValidator(val)
 		if evc != nil {
-			evc.FireEvent(types.EventStringRebond(), tx)
+			evc.FireEvent(types.EventStringRebond(), types.EventDataTx{tx, nil, ""})
 		}
 		return nil
 
@@ -803,7 +803,7 @@ func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireab
 		// Good! (Bad validator!)
 		_s.destroyValidator(accused)
 		if evc != nil {
-			evc.FireEvent(types.EventStringDupeout(), tx)
+			evc.FireEvent(types.EventStringDupeout(), types.EventDataTx{tx, nil, ""})
 		}
 		return nil
 
@@ -894,7 +894,7 @@ func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireab
 
 		if evc != nil {
 			evc.FireEvent(types.EventStringAccInput(tx.Input.Address), types.EventDataTx{tx, nil, ""})
-			evc.FireEvent(types.EventStringPermissions(ptypes.PermFlagToString(permFlag)), tx)
+			evc.FireEvent(types.EventStringPermissions(ptypes.PermFlagToString(permFlag)), types.EventDataTx{tx, nil, ""})
 		}
 
 		return nil
diff --git a/state/permissions_test.go b/state/permissions_test.go
index 057b17000..59404fadc 100644
--- a/state/permissions_test.go
+++ b/state/permissions_test.go
@@ -1055,7 +1055,7 @@ func execTxWaitEvent(t *testing.T, blockCache *BlockCache, tx types.Tx, eventid
 	evsw := events.NewEventSwitch()
 	evsw.Start()
 	ch := make(chan interface{})
-	evsw.AddListenerForEvent("test", eventid, func(msg interface{}) {
+	evsw.AddListenerForEvent("test", eventid, func(msg types.EventData) {
 		ch <- msg
 	})
 	evc := events.NewEventCache(evsw)
diff --git a/state/tx_cache.go b/state/tx_cache.go
index 4d7f20c18..8afd1cd0a 100644
--- a/state/tx_cache.go
+++ b/state/tx_cache.go
@@ -12,7 +12,6 @@ type TxCache struct {
 	backend  *BlockCache
 	accounts map[Word256]vmAccountInfo
 	storages map[Tuple256]Word256
-	logs     []types.EventDataLog
 }
 
 func NewTxCache(backend *BlockCache) *TxCache {
@@ -20,7 +19,6 @@ func NewTxCache(backend *BlockCache) *TxCache {
 		backend:  backend,
 		accounts: make(map[Word256]vmAccountInfo),
 		storages: make(map[Tuple256]Word256),
-		logs:     make([]types.EventDataLog, 0),
 	}
 }
 
@@ -138,10 +136,6 @@ func (cache *TxCache) Sync() {
 	}
 }
 
-func (cache *TxCache) AddLog(log types.EventDataLog) {
-	cache.logs = append(cache.logs, log)
-}
-
 //-----------------------------------------------------------------------------
 
 // Convenience function to return address of new contract
diff --git a/types/events.go b/types/events.go
index d37dc27c1..0b053cc42 100644
--- a/types/events.go
+++ b/types/events.go
@@ -14,6 +14,7 @@ func EventStringAccOutput(addr []byte) string   { return fmt.Sprintf("Acc/%X/Out
 func EventStringAccCall(addr []byte) string     { return fmt.Sprintf("Acc/%X/Call", addr) }
 func EventStringLogEvent(addr []byte) string    { return fmt.Sprintf("Log/%X", addr) }
 func EventStringPermissions(name string) string { return fmt.Sprintf("Permissions/%s", name) }
+func EventStringNameReg(name string) string     { return fmt.Sprintf("NameReg/%s", name) }
 func EventStringBond() string                   { return "Bond" }
 func EventStringUnbond() string                 { return "Unbond" }
 func EventStringRebond() string                 { return "Rebond" }
@@ -31,12 +32,14 @@ const (
 	EventDataTypeLog      = byte(0x05)
 )
 
-type EventData interface{}
+type EventData interface {
+	AssertIsEventData()
+}
 
 var _ = wire.RegisterInterface(
 	struct{ EventData }{},
 	wire.ConcreteType{EventDataNewBlock{}, EventDataTypeNewBlock},
-	// wire.ConcreteType{EventDataNewBlock{}, EventDataTypeFork },
+	// wire.ConcreteType{EventDataFork{}, EventDataTypeFork },
 	wire.ConcreteType{EventDataTx{}, EventDataTypeTx},
 	wire.ConcreteType{EventDataCall{}, EventDataTypeCall},
 	wire.ConcreteType{EventDataLog{}, EventDataTypeLog},
@@ -80,3 +83,8 @@ type EventDataLog struct {
 	Data    []byte    `json:"data"`
 	Height  int64     `json:"height"`
 }
+
+func (_ EventDataNewBlock) AssertIsEventData() {}
+func (_ EventDataTx) AssertIsEventData()       {}
+func (_ EventDataCall) AssertIsEventData()     {}
+func (_ EventDataLog) AssertIsEventData()      {}
diff --git a/vm/test/fake_app_state.go b/vm/test/fake_app_state.go
index f9661505a..72dcca58e 100644
--- a/vm/test/fake_app_state.go
+++ b/vm/test/fake_app_state.go
@@ -2,7 +2,6 @@ package vm
 
 import (
 	. "github.com/tendermint/tendermint/common"
-	"github.com/tendermint/tendermint/types"
 	. "github.com/tendermint/tendermint/vm"
 	"github.com/tendermint/tendermint/vm/sha3"
 )
@@ -10,7 +9,6 @@ import (
 type FakeAppState struct {
 	accounts map[string]*Account
 	storage  map[string]Word256
-	logs     []types.EventDataLog
 }
 
 func (fas *FakeAppState) GetAccount(addr Word256) *Account {
@@ -70,10 +68,6 @@ func (fas *FakeAppState) SetStorage(addr Word256, key Word256, value Word256) {
 	fas.storage[addr.String()+key.String()] = value
 }
 
-func (fas *FakeAppState) AddLog(log types.EventDataLog) {
-	fas.logs = append(fas.logs, log)
-}
-
 // Creates a 20 byte address and bumps the nonce.
 func createAddress(creator *Account) Word256 {
 	nonce := creator.Nonce
diff --git a/vm/test/log_event_test.go b/vm/test/log_event_test.go
index 6107de52c..2e3f83376 100644
--- a/vm/test/log_event_test.go
+++ b/vm/test/log_event_test.go
@@ -44,7 +44,7 @@ func TestLog4(t *testing.T) {
 
 	doneChan := make(chan struct{}, 1)
 
-	eventSwitch.AddListenerForEvent("test", eventId, func(event interface{}) {
+	eventSwitch.AddListenerForEvent("test", eventId, func(event types.EventData) {
 		logEvent := event.(types.EventDataLog)
 		// No need to test address as this event would not happen if it wasn't correct
 		if !reflect.DeepEqual(logEvent.Topics, expectedTopics) {
diff --git a/vm/test/vm_test.go b/vm/test/vm_test.go
index 4ea33e3ea..dc268a6a3 100644
--- a/vm/test/vm_test.go
+++ b/vm/test/vm_test.go
@@ -19,7 +19,6 @@ func newAppState() *FakeAppState {
 	fas := &FakeAppState{
 		accounts: make(map[string]*Account),
 		storage:  make(map[string]Word256),
-		logs:     nil,
 	}
 	// For default permissions
 	fas.accounts[ptypes.GlobalPermissionsAddress256.String()] = &Account{
@@ -158,7 +157,7 @@ func runVMWaitEvents(t *testing.T, ourVm *VM, caller, callee *Account, subscribe
 	evsw.Start()
 	ch := make(chan interface{})
 	fmt.Printf("subscribe to %x\n", subscribeAddr)
-	evsw.AddListenerForEvent("test", types.EventStringAccCall(subscribeAddr), func(msg interface{}) {
+	evsw.AddListenerForEvent("test", types.EventStringAccCall(subscribeAddr), func(msg types.EventData) {
 		ch <- msg
 	})
 	evc := events.NewEventCache(evsw)
diff --git a/vm/types.go b/vm/types.go
index 74074a423..cb9bc64ff 100644
--- a/vm/types.go
+++ b/vm/types.go
@@ -3,7 +3,6 @@ package vm
 import (
 	. "github.com/tendermint/tendermint/common"
 	ptypes "github.com/tendermint/tendermint/permission/types"
-	"github.com/tendermint/tendermint/types"
 )
 
 const (
@@ -40,8 +39,6 @@ type AppState interface {
 	GetStorage(Word256, Word256) Word256
 	SetStorage(Word256, Word256, Word256) // Setting to Zero is deleting.
 
-	// Logs
-	AddLog(types.EventDataLog)
 }
 
 type Params struct {
diff --git a/vm/vm.go b/vm/vm.go
index 405692755..ea06825b2 100644
--- a/vm/vm.go
+++ b/vm/vm.go
@@ -694,20 +694,18 @@ func (vm *VM) call(caller, callee *Account, code, input []byte, value int64, gas
 			if !ok {
 				return nil, firstErr(err, ErrMemoryOutOfBounds)
 			}
-			log := types.EventDataLog{
-				callee.Address,
-				topics,
-				data,
-				vm.params.BlockHeight,
-			}
-			vm.appState.AddLog(log)
 			if vm.evc != nil {
 				eventId := types.EventStringLogEvent(callee.Address.Postfix(20))
 				fmt.Printf("eventId: %s\n", eventId)
+				log := types.EventDataLog{
+					callee.Address,
+					topics,
+					data,
+					vm.params.BlockHeight,
+				}
 				vm.evc.FireEvent(eventId, log)
 			}
-			// Using sol-log for this as well since 'log' will print garbage.
-			dbg.Printf(" => T:%X D:%X\n", log.Topics, log.Data)
+			dbg.Printf(" => T:%X D:%X\n", topics, data)
 
 		case CREATE: // 0xF0
 			if !HasPermission(vm.appState, callee, ptypes.CreateContract) {
diff --git a/wire/reflect.go b/wire/reflect.go
index c7745a4e5..f8f916f37 100644
--- a/wire/reflect.go
+++ b/wire/reflect.go
@@ -419,11 +419,14 @@ func writeReflectBinary(rv reflect.Value, rt reflect.Type, opts Options, w io.Wr
 			if !ok {
 				switch crt.Kind() {
 				case reflect.Ptr:
-					*err = errors.New(Fmt("Unexpected pointer type %v. Was it registered as a value receiver rather than as a pointer receiver?", crt))
+					*err = errors.New(Fmt("Unexpected pointer type %v for registered interface %v. "+
+						"Was it registered as a value receiver rather than as a pointer receiver?", crt, rt.Name()))
 				case reflect.Struct:
-					*err = errors.New(Fmt("Unexpected struct type %v. Was it registered as a pointer receiver rather than as a value receiver?", crt))
+					*err = errors.New(Fmt("Unexpected struct type %v for registered interface %v. "+
+						"Was it registered as a pointer receiver rather than as a value receiver?", crt, rt.Name()))
 				default:
-					*err = errors.New(Fmt("Unexpected type %v.", crt))
+					*err = errors.New(Fmt("Unexpected type %v for registered interface %v. "+
+						"If this is intentional, please register it.", crt, rt.Name()))
 				}
 				return
 			}
@@ -819,11 +822,14 @@ func writeReflectJSON(rv reflect.Value, rt reflect.Type, w io.Writer, n *int64,
 			if !ok {
 				switch crt.Kind() {
 				case reflect.Ptr:
-					*err = errors.New(Fmt("Unexpected pointer type %v. Was it registered as a value receiver rather than as a pointer receiver?", crt))
+					*err = errors.New(Fmt("Unexpected pointer type %v for registered interface %v. "+
+						"Was it registered as a value receiver rather than as a pointer receiver?", crt, rt.Name()))
 				case reflect.Struct:
-					*err = errors.New(Fmt("Unexpected struct type %v. Was it registered as a pointer receiver rather than as a value receiver?", crt))
+					*err = errors.New(Fmt("Unexpected struct type %v for registered interface %v. "+
+						"Was it registered as a pointer receiver rather than as a value receiver?", crt, rt.Name()))
 				default:
-					*err = errors.New(Fmt("Unexpected type %v.", crt))
+					*err = errors.New(Fmt("Unexpected type %v for registered interface %v. "+
+						"If this is intentional, please register it.", crt, rt.Name()))
 				}
 				return
 			}