diff --git a/packages/core/src/internal/BehaviorObservable.ts b/packages/core/src/internal/BehaviorObservable.ts
index f62a1c8..fa14757 100644
--- a/packages/core/src/internal/BehaviorObservable.ts
+++ b/packages/core/src/internal/BehaviorObservable.ts
@@ -3,3 +3,9 @@ import { Observable } from "rxjs"
 export interface BehaviorObservable<T> extends Observable<T> {
   getValue: () => any
 }
+
+export const enum Action {
+  Error,
+  Value,
+  Suspense,
+}
diff --git a/packages/core/src/internal/react-enhancer.ts b/packages/core/src/internal/react-enhancer.ts
index ecba076..288cb12 100644
--- a/packages/core/src/internal/react-enhancer.ts
+++ b/packages/core/src/internal/react-enhancer.ts
@@ -1,7 +1,7 @@
 import { Observable, noop } from "rxjs"
 import { take, filter, tap } from "rxjs/operators"
 import { SUSPENSE } from "../SUSPENSE"
-import { BehaviorObservable } from "./BehaviorObservable"
+import { BehaviorObservable, Action } from "./BehaviorObservable"
 import { EMPTY_VALUE } from "./empty-value"
 
 const reactEnhancer = <T>(source$: Observable<T>): BehaviorObservable<T> => {
@@ -42,9 +42,11 @@ const reactEnhancer = <T>(source$: Observable<T>): BehaviorObservable<T> => {
     }
   }) as BehaviorObservable<T>
 
-  let promise: any
-  let error = EMPTY_VALUE
-  const getValue = () => {
+  let promise: undefined | { type: Action.Suspense; payload: Promise<T | void> }
+  let error:
+    | typeof EMPTY_VALUE
+    | { type: Action.Error; payload: any } = EMPTY_VALUE
+  const getValue = (): { type: Action; payload: any } => {
     let timeoutToken
     if (error !== EMPTY_VALUE) {
       clearTimeout(timeoutToken)
@@ -56,25 +58,27 @@ const reactEnhancer = <T>(source$: Observable<T>): BehaviorObservable<T> => {
 
     try {
       return {
-        type: "v",
+        type: Action.Value,
         payload: (source$ as BehaviorObservable<T>).getValue(),
       }
     } catch (e) {
       if (promise) return promise
 
-      let value = EMPTY_VALUE
+      let value:
+        | typeof EMPTY_VALUE
+        | { type: Action.Value; payload: T } = EMPTY_VALUE
       promise = {
-        type: "s",
+        type: Action.Suspense,
         payload: result
           .pipe(
             filter((x) => x !== (SUSPENSE as any)),
             take(1),
             tap({
               next(v) {
-                value = { type: "v", payload: v }
+                value = { type: Action.Value, payload: v }
               },
               error(e) {
-                error = { type: "e", payload: e }
+                error = { type: Action.Error, payload: e }
                 timeoutToken = setTimeout(() => {
                   error = EMPTY_VALUE
                 }, 50)
@@ -99,7 +103,7 @@ const reactEnhancer = <T>(source$: Observable<T>): BehaviorObservable<T> => {
       return promise
     }
   }
-  result.getValue = getValue as () => T | Promise<T>
+  result.getValue = getValue
   return result
 }
 
diff --git a/packages/core/src/internal/useObservable.ts b/packages/core/src/internal/useObservable.ts
index 985eae7..2acfe5d 100644
--- a/packages/core/src/internal/useObservable.ts
+++ b/packages/core/src/internal/useObservable.ts
@@ -1,12 +1,8 @@
 import { useEffect, useReducer } from "react"
-import { BehaviorObservable } from "./BehaviorObservable"
+import { BehaviorObservable, Action } from "./BehaviorObservable"
 import { SUSPENSE } from "../SUSPENSE"
 import { Observable } from "rxjs"
 
-const ERROR: "e" = "e"
-const VALUE: "v" = "v"
-type Action = "e" | "v" | "s"
-
 const reducer = (
   current: { type: Action; payload: any },
   action: { type: Action; payload: any },
@@ -47,14 +43,14 @@ export const useObservable = <O>(
           dispatch(source$.getValue())
         } else {
           dispatch({
-            type: VALUE,
+            type: Action.Value,
             payload: value,
           })
         }
       },
       (error) =>
         dispatch({
-          type: ERROR,
+          type: Action.Error,
           payload: error,
         }),
     )
@@ -62,6 +58,6 @@ export const useObservable = <O>(
   }, [source$])
 
   const { type, payload } = state
-  if (type === VALUE) return payload
+  if (type === Action.Value) return payload
   throw payload
 }
diff --git a/packages/utils/src/collect.ts b/packages/utils/src/collect.ts
index 94c4498..5179e67 100644
--- a/packages/utils/src/collect.ts
+++ b/packages/utils/src/collect.ts
@@ -7,7 +7,7 @@ import {
   distinctUntilChanged,
   skipWhile,
 } from "rxjs/operators"
-import { set, del, collector } from "./internal-utils"
+import { CollectorAction, collector } from "./internal-utils"
 
 const defaultFilter = (source$: Observable<any>) =>
   source$.pipe(ignoreElements(), startWith(true), endWith(false))
@@ -37,6 +37,12 @@ export const collect = <K, V>(
 
   return (source$: Observable<GroupedObservable<K, V>>) =>
     collector(source$, (o) =>
-      map((x) => ({ t: x ? set : del, k: o.key, v: o }))(enhancer(o)),
+      map((x) => ({
+        t: x
+          ? (CollectorAction.Set as const)
+          : (CollectorAction.Delete as const),
+        k: o.key,
+        v: o,
+      }))(enhancer(o)),
     )
 }
diff --git a/packages/utils/src/collectValues.ts b/packages/utils/src/collectValues.ts
index 30a75cb..120fbc0 100644
--- a/packages/utils/src/collectValues.ts
+++ b/packages/utils/src/collectValues.ts
@@ -1,6 +1,6 @@
 import { Observable, GroupedObservable, OperatorFunction } from "rxjs"
 import { map, endWith } from "rxjs/operators"
-import { set, del, collector } from "./internal-utils"
+import { CollectorAction, collector } from "./internal-utils"
 
 /**
  * A pipeable operator that collects all the GroupedObservables emitted by
@@ -12,7 +12,7 @@ export const collectValues = <K, V>(): OperatorFunction<
 > => (source$: Observable<GroupedObservable<K, V>>): Observable<Map<K, V>> =>
   collector(source$, (inner$) =>
     inner$.pipe(
-      map((v) => ({ t: set, k: inner$.key, v })),
-      endWith({ t: del, k: inner$.key }),
+      map((v) => ({ t: CollectorAction.Set as const, k: inner$.key, v })),
+      endWith({ t: CollectorAction.Delete, k: inner$.key }),
     ),
   )
diff --git a/packages/utils/src/internal-utils.ts b/packages/utils/src/internal-utils.ts
index bed7003..a5d8404 100644
--- a/packages/utils/src/internal-utils.ts
+++ b/packages/utils/src/internal-utils.ts
@@ -37,24 +37,29 @@ export const scanWithDefaultValue = <I, O>(
     return source.pipe(scan(accumulator, seed), defaultStart(seed))
   })
 
-export const set = "s" as const
-export const del = "d" as const
-export const complete = "c" as const
+export const enum CollectorAction {
+  Set,
+  Delete,
+  Complete,
+}
 
 export const collector = <K, V, VV>(
   source: Observable<GroupedObservable<K, V>>,
   enhancer: (
     source: GroupedObservable<K, V>,
-  ) => Observable<{ t: "d"; k: K } | { t: "s"; k: K; v: VV }>,
+  ) => Observable<
+    | { t: CollectorAction.Delete; k: K }
+    | { t: CollectorAction.Set; k: K; v: VV }
+  >,
 ): Observable<Map<K, VV>> =>
   source.pipe(
     publish((x) => x.pipe(mergeMap(enhancer), takeUntil(takeLast(1)(x)))),
-    endWith({ t: complete }),
+    endWith({ t: CollectorAction.Complete as const }),
     scanWithDefaultValue(
       (acc, val) => {
-        if (val.t === set) {
+        if (val.t === CollectorAction.Set) {
           acc.set(val.k, val.v)
-        } else if (val.t === del) {
+        } else if (val.t === CollectorAction.Delete) {
           acc.delete(val.k)
         } else {
           acc.clear()