diff --git a/browser/config/mozconfigs/win64/code-coverage b/browser/config/mozconfigs/win64/code-coverage
index 94035cc55b13..b873039483c1 100644
--- a/browser/config/mozconfigs/win64/code-coverage
+++ b/browser/config/mozconfigs/win64/code-coverage
@@ -29,6 +29,7 @@ fi
 
 export CFLAGS="--coverage"
 export CXXFLAGS="--coverage"
+export RUSTFLAGS="-Ccodegen-units=1 -Zprofile -Zno-landing-pads"
 
 . "$topsrcdir/build/mozconfig.common.override"
 . "$topsrcdir/build/mozconfig.clang-cl"