--- a/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp
+++ b/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp
@@ -452,6 +452,7 @@
   // Various places where fonts reside
   policy->AddDir(rdonly, "/usr/X11R6/lib/X11/fonts");
   policy->AddDir(rdonly, "/nix/store");
+  policy->AddDir(rdonly, "/gnu/store");
   // https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/blob/e434e680d22260f277f4a30ec4660ed32b591d16/files/fontconfig-flatpak.conf
   policy->AddDir(rdonly, "/run/host/fonts");
   policy->AddDir(rdonly, "/run/host/user-fonts");
@@ -461,6 +462,7 @@
   // Bug 1848615
   policy->AddPath(rdonly, "/usr");
   policy->AddPath(rdonly, "/nix");
+  policy->AddPath(rdonly, "/gnu");
 
   AddLdconfigPaths(policy);
   AddLdLibraryEnvPaths(policy);
@@ -920,6 +922,7 @@
   policy->AddDir(rdonly, "/usr/lib64");
   policy->AddDir(rdonly, "/run/opengl-driver/lib");
   policy->AddDir(rdonly, "/nix/store");
+  policy->AddDir(rdonly, "/gnu/store");
 
   // Bug 1647957: memory reporting.
   AddMemoryReporting(policy.get(), aPid);
@@ -1043,6 +1046,7 @@
   // Required to make sure ffmpeg loads properly, this is already existing on
   // Content and RDD
   policy->AddDir(rdonly, "/nix/store");
+  policy->AddDir(rdonly, "/gnu/store");
 
   // glibc will try to stat64("/") while populating nsswitch database
   // https://sourceware.org/git/?p=glibc.git;a=blob;f=nss/nss_database.c;h=cf0306adc47f12d9bc761ab1b013629f4482b7e6;hb=9826b03b747b841f5fc6de2054bf1ef3f5c4bdf3#l396