diff --git a/src/actions/__tests__/index_spec.ts b/src/actions/__tests__/index_spec.ts
index 6354ad9..e8d1061 100644
--- a/src/actions/__tests__/index_spec.ts
+++ b/src/actions/__tests__/index_spec.ts
@@ -69,7 +69,7 @@ describe('actions', () => {
         const { dispatch, reducer } = store()
         actions.saveCount({ value: 14 })(dispatch)
         return eventually(() => {
-          expect(reducer.mock.calls[1][1].error.message)
+          expect(reducer.mock.calls[1][1].error)
             .toEqual('something terrible happened')
         })
       })
@@ -131,7 +131,7 @@ describe('actions', () => {
         const { dispatch, reducer } = store()
         actions.loadCount()(dispatch)
         return eventually(() => {
-          expect(reducer.mock.calls[1][1].error.message)
+          expect(reducer.mock.calls[1][1].error)
             .toEqual('something terrible happened')
         })
       })
diff --git a/src/actions/action.ts b/src/actions/action.ts
index ec6cc31..a3d28d3 100644
--- a/src/actions/action.ts
+++ b/src/actions/action.ts
@@ -1,29 +1,28 @@
 type Q<T> = { request: T }
 type S<T> = { response: T }
-type E = { error: Error }
+type E = { error: string }
 
-type QEmpty = Q<{}>
-type QValue = Q<{ value: number }>
+type Value = { value: number }
 
-type LoadCount =
-    ({ type: 'LOAD_COUNT_REQUEST' } & QEmpty)
-  | ({ type: 'LOAD_COUNT_SUCCESS' } & QEmpty & S<{ value: number }>)
-  | ({ type: 'LOAD_COUNT_ERROR'   } & QEmpty & E)
+type LoadCountAction =
+  ({ type: 'LOAD_COUNT_REQUEST' } & Q<{}>)
+| ({ type: 'LOAD_COUNT_SUCCESS' } & Q<{}> & S<Value>)
+| ({ type: 'LOAD_COUNT_ERROR'   } & Q<{}> & E)
 
-type SaveCount =
-    ({ type: 'SAVE_COUNT_REQUEST' } & QValue)
-  | ({ type: 'SAVE_COUNT_SUCCESS' } & QValue & S<{}>)
-  | ({ type: 'SAVE_COUNT_ERROR'   } & QValue & E)
+type SaveCountAction =
+  ({ type: 'SAVE_COUNT_REQUEST' } & Q<Value>)
+| ({ type: 'SAVE_COUNT_SUCCESS' } & Q<Value> & S<{}>)
+| ({ type: 'SAVE_COUNT_ERROR'   } & Q<Value> & E)
 
 export type Action =
-  LoadCount
-| SaveCount
+  LoadCountAction
+| SaveCountAction
 | { type: 'INCREMENT_COUNTER', delta: number }
 | { type: 'RESET_COUNTER' }
 
 type _T = Action['type']
 
-type APIActionGroup<TQ extends _T, TS extends _T, TE extends _T, _Q, _S> =
+type ThunkActionGroup<TQ extends _T, TS extends _T, TE extends _T, _Q, _S> =
   ({ type: TQ } & Q<_Q>)
 | ({ type: TS } & Q<_Q> & S<_S>)
 | ({ type: TE } & Q<_Q> & E)
@@ -34,9 +33,9 @@ type Thunk<Q, S> = (request: Q) => Promise<S>
 export const createThunkAction = <Q, S, TQ extends _T, TS extends _T, TE extends _T>
   (fn: Thunk<Q, S>, tq: TQ, ts: TS, te: TE) =>
     (request: Q) =>
-      (dispatch: Dispatch<APIActionGroup<TQ, TS, TE, Q, S>>) => {
+      (dispatch: Dispatch<ThunkActionGroup<TQ, TS, TE, Q, S>>) => {
         dispatch({ type: tq, request })
         fn(request)
           .then(response => dispatch({ type: ts, request, response }))
-          .catch(error => dispatch({ type: te, request, error }))
+          .catch(err => dispatch({ type: te, request, error: err.message }))
       }
diff --git a/src/reducers/index.ts b/src/reducers/index.ts
index ce99663..bbb30b3 100644
--- a/src/reducers/index.ts
+++ b/src/reducers/index.ts
@@ -42,7 +42,7 @@ function error (state: string = '', action: Action): string {
       return ''
     case 'LOAD_COUNT_ERROR':
     case 'SAVE_COUNT_ERROR':
-      return action.error.toString()
+      return action.error
     default:
       return state
   }