diff --git a/devtools/client/debugger/src/actions/navigation.js b/devtools/client/debugger/src/actions/navigation.js
index a6ed37c7b03d..3e519cd071c2 100644
--- a/devtools/client/debugger/src/actions/navigation.js
+++ b/devtools/client/debugger/src/actions/navigation.js
@@ -48,7 +48,7 @@ export function willNavigate(event: Object) {
 export function connect(
   url: string,
   actor: string,
-  canRewind: boolean,
+  traits,
   isWebExtension: boolean
 ) {
   return async function({ dispatch }: ThunkArgs) {
@@ -62,7 +62,7 @@ export function connect(
           type: "mainThread",
           name: L10N.getStr("mainThread"),
         },
-        canRewind,
+        traits,
         isWebExtension,
       }: Action)
     );
diff --git a/devtools/client/debugger/src/actions/sources/newSources.js b/devtools/client/debugger/src/actions/sources/newSources.js
index f10bbcf7aa3f..6fe2dd473605 100644
--- a/devtools/client/debugger/src/actions/sources/newSources.js
+++ b/devtools/client/debugger/src/actions/sources/newSources.js
@@ -291,7 +291,6 @@ export function newGeneratedSources(sourceInfo: Array<GeneratedSourceData>) {
     getState,
     client,
   }: ThunkArgs): Promise<Array<Source>> => {
-    const supportsWasm = client.hasWasmSupport();

     const resultIds = [];
     const newSourcesObj = {};
@@ -310,7 +309,7 @@ export function newGeneratedSources(sourceInfo: Array<GeneratedSourceData>) {
           introductionUrl: source.introductionUrl,
           introductionType: source.introductionType,
           isBlackBoxed: false,
-          isWasm: !!supportsWasm && source.introductionType === "wasm",
+          isWasm: !!supportsWasm(getState()) && source.introductionType === "wasm",
           isExtension: (source.url && isUrlExtension(source.url)) || false,
         };
       }
diff --git a/devtools/client/debugger/src/client/firefox.js b/devtools/client/debugger/src/client/firefox.js
index d79c76f2b797..24db2e5033d5 100644
--- a/devtools/client/debugger/src/client/firefox.js
+++ b/devtools/client/debugger/src/client/firefox.js
@@ -25,14 +25,10 @@ export async function onConnect(connection: any, actions: Object) {
     return;
   }

-  const supportsWasm =
-    features.wasm && !!debuggerClient.mainRoot.traits.wasmBinarySource;
-
   setupCommands({
     threadFront,
     tabTarget,
     debuggerClient,
-    supportsWasm,
   });

   setupEvents({ threadFront, tabTarget, actions, supportsWasm });
@@ -59,7 +55,7 @@ export async function onConnect(connection: any, actions: Object) {
   await actions.connect(
     tabTarget.url,
     threadFront.actor,
-    traits && traits.canRewind,
+    traits,
     tabTarget.isWebExtension
   );

diff --git a/devtools/client/debugger/src/client/firefox/commands.js b/devtools/client/debugger/src/client/firefox/commands.js
index 7daea96bc12e..0c7fe3b256b0 100644
--- a/devtools/client/debugger/src/client/firefox/commands.js
+++ b/devtools/client/debugger/src/client/firefox/commands.js
@@ -48,29 +48,22 @@ let debuggerClient: DebuggerClient;
 let sourceActors: { [ActorId]: SourceId };
 let breakpoints: { [string]: Object };
 let eventBreakpoints: ?EventListenerActiveList;
-let supportsWasm: boolean;

 type Dependencies = {
   threadFront: ThreadFront,
   tabTarget: Target,
   debuggerClient: DebuggerClient,
-  supportsWasm: boolean,
 };

 function setupCommands(dependencies: Dependencies) {
   currentThreadFront = dependencies.threadFront;
   currentTarget = dependencies.tabTarget;
   debuggerClient = dependencies.debuggerClient;
-  supportsWasm = dependencies.supportsWasm;
   targets = { worker: {}, contentProcess: {} };
   sourceActors = {};
   breakpoints = {};
 }

-function hasWasmSupport() {
-  return supportsWasm;
-}
-
 function createObjectClient(grip: Grip) {
   return debuggerClient.createObjectClient(grip);
 }
@@ -589,7 +582,6 @@ const clientCommands = {
   setEventListenerBreakpoints,
   getEventListenerBreakpointTypes,
   detachWorkers,
-  hasWasmSupport,
   lookupTarget,
 };

diff --git a/devtools/client/debugger/src/reducers/pause.js b/devtools/client/debugger/src/reducers/pause.js
index 226e20ca2881..ce271243e89b 100644
--- a/devtools/client/debugger/src/reducers/pause.js
+++ b/devtools/client/debugger/src/reducers/pause.js
@@ -91,7 +91,6 @@ type ThreadPauseState = {
 export type PauseState = {
   cx: Context,
   threadcx: ThreadContext,
-  canRewind: boolean,
   threads: { [ThreadId]: ThreadPauseState },
   skipPausing: boolean,
   mapScopes: boolean,
@@ -113,7 +112,6 @@ function createPauseState(thread: ThreadId = "UnknownThread") {
     },
     previewLocation: null,
     threads: {},
-    canRewind: false,
     skipPausing: prefs.skipPausing,
     mapScopes: prefs.mapScopes,
     shouldPauseOnExceptions: prefs.pauseOnExceptions,
@@ -136,7 +134,6 @@ const resumedPauseState = {
 const createInitialPauseState = () => ({
   ...resumedPauseState,
   isWaitingOnBreak: false,
-  canRewind: false,
   command: null,
   lastCommand: null,
   previousLocation: null,
@@ -279,7 +276,6 @@ function update(
     case "CONNECT":
       return {
         ...createPauseState(action.mainThread.actor),
-        canRewind: action.canRewind,
       };

     case "PAUSE_ON_EXCEPTIONS": {
@@ -485,10 +481,6 @@ export function getShouldPauseOnCaughtExceptions(state: State) {
   return state.pause.shouldPauseOnCaughtExceptions;
 }

-export function getCanRewind(state: State) {
-  return state.pause.canRewind;
-}
-
 export function getFrames(state: State, thread: ThreadId) {
   return getThreadPauseState(state.pause, thread).frames;
 }
diff --git a/devtools/client/debugger/src/reducers/threads.js b/devtools/client/debugger/src/reducers/threads.js
index 4e2ae25635cd..b3bef6516f78 100644
--- a/devtools/client/debugger/src/reducers/threads.js
+++ b/devtools/client/debugger/src/reducers/threads.js
@@ -25,6 +25,7 @@ export type ThreadsState = {
 export function initialThreadsState(): ThreadsState {
   return {
     threads: [],
+    traits: {},
     mainThread: {
       actor: "",
       url: "",
@@ -44,6 +45,7 @@ export default function update(
       return {
         ...state,
         mainThread: action.mainThread,
+        traits, action.traits,
         isWebExtension: action.isWebExtension,
       };
     case "INSERT_THREADS":
@@ -92,6 +94,16 @@ export const getAllThreads: Selector<Thread[]> = createSelector(
   ]
 );

+
+export function getCanRewind(state: State) {
+  return state.threads.traits.canRewind;
+}
+
+export function supportsWasm(state: State) {
+  return features.wasm && state.threads.traits.wasmBinarySource;
+}
+
+
 // checks if a path begins with a thread actor
 // e.g "server1.conn0.child1/workerTarget22/context1/dbg-workers.glitch.me"
 export function startsWithThreadActor(state: State, path: string) {
@@ -101,4 +113,8 @@ export function startsWithThreadActor(state: State, path: string) {
   return match && match[1];
 }

+
+
 type OuterState = { threads: ThreadsState };
+
+