diff --git a/firefox.spec b/firefox.spec
index a640b62..539ddf6 100644
--- a/firefox.spec
+++ b/firefox.spec
@@ -310,7 +310,7 @@ BuildRequires:  rust >= %{rust_version}
 
 %if 0%{?rhel} == 9
 BuildRequires:  cargo
-BuildRequires:  clang clang-libs llvm
+BuildRequires:  clang clang-libs llvm llvm-devel
 BuildRequires:  gcc
 BuildRequires:  gcc-c++
 BuildRequires:  python3-devel