diff --git a/www-client/firefox/firefox-94.0.ebuild b/www-client/firefox/firefox-94.0.ebuild
index adbc1566ba3..f9fce1f0e1f 100644
--- a/www-client/firefox/firefox-94.0.ebuild
+++ b/www-client/firefox/firefox-94.0.ebuild
@@ -85,15 +85,8 @@ BDEPEND="${PYTHON_DEPS}
 	>=net-libs/nodejs-10.23.1
 	virtual/pkgconfig
 	>=virtual/rust-1.51.0
+	<virtual/rust-1.56
 	|| (
-		(
-			sys-devel/clang:13
-			sys-devel/llvm:13
-			clang? (
-				=sys-devel/lld-13*
-				pgo? ( =sys-libs/compiler-rt-sanitizers-13*[profile] )
-			)
-		)
 		(
 			sys-devel/clang:12
 			sys-devel/llvm:12
@@ -448,7 +441,7 @@ pkg_setup() {
 
 		check-reqs_pkg_setup
 
-		llvm_pkg_setup
+		LLVM_MAX_SLOT=12 llvm_pkg_setup
 
 		if use clang && use lto ; then
 			local version_lld=$(ld.lld --version 2>/dev/null | awk '{ print $2 }')