diff --git a/.eslintrc.js b/.eslintrc.js
index 184f6ce89..445ee523c 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -195,6 +195,7 @@ module.exports = {
         'babel.config.js',
         'nyc.config.js',
         'stylelint.config.js',
+        'app/scripts/runLockdown.js',
         'development/**/*.js',
         'test/e2e/**/*.js',
         'test/lib/wait-until-called.js',
diff --git a/app/scripts/runLockdown.js b/app/scripts/runLockdown.js
index d8584c69c..210005967 100644
--- a/app/scripts/runLockdown.js
+++ b/app/scripts/runLockdown.js
@@ -1,8 +1,19 @@
 // Freezes all intrinsics
-// eslint-disable-next-line no-undef,import/unambiguous
-lockdown({
-  consoleTaming: 'unsafe',
-  errorTaming: 'unsafe',
-  mathTaming: 'unsafe',
-  dateTaming: 'unsafe',
-})
+try {
+  // eslint-disable-next-line no-undef,import/unambiguous
+  lockdown({
+    consoleTaming: 'unsafe',
+    errorTaming: 'unsafe',
+    mathTaming: 'unsafe',
+    dateTaming: 'unsafe',
+  })
+} catch (error) {
+  // If the `lockdown` call throws an exception, it interferes with the
+  // contentscript injection on some versions of Firefox. The error is
+  // caught and logged here so that the contentscript still gets injected.
+  // This affects Firefox v56 and Waterfox Classic
+  console.error('Lockdown failed:', error)
+  if (window.sentry && window.sentry.captureException) {
+    window.sentry.captureException(error)
+  }
+}