diff --git a/.eslintrc.js b/.eslintrc.js
index da3bcdac05f7..be52cbcbb7be 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -45,7 +45,6 @@ module.exports = {
   "overrides": [{
       "files": [
         "devtools/**",
-        "mfbt/**",
         "mobile/**",
         "modules/**",
         "mozglue/**",
diff --git a/.prettierignore b/.prettierignore
index d512a48c9c7f..624011cfd261 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -40,7 +40,6 @@ toolkit/components/telemetry/datareporting-prefs.js
 toolkit/components/telemetry/healthreport-prefs.js
 
 # Ignore all top-level directories for now.
-mfbt/**
 mobile/**
 modules/**
 mozglue/**