--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2633,21 +2633,17 @@ pref("security.csp.enable_violation_even
 // Default Content Security Policy to apply to signed contents.
 pref("security.signed_content.CSP.default", "script-src 'self'; style-src 'self'");
 
 // Mixed content blocking
 pref("security.mixed_content.block_active_content", false);
 pref("security.mixed_content.block_display_content", false);
 
 // Upgrade mixed display content before it's blocked
-#ifdef NIGHTLY_BUILD
-pref("security.mixed_content.upgrade_display_content", true);
-#else
 pref("security.mixed_content.upgrade_display_content", false);
-#endif
 
 // Block sub requests that happen within an object
 #ifdef EARLY_BETA_OR_EARLIER
 pref("security.mixed_content.block_object_subrequest", true);
 #else
 pref("security.mixed_content.block_object_subrequest", false);
 #endif