diff --git a/thunderbird.spec b/thunderbird.spec
index cf25282..57ba8b4 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -293,7 +293,7 @@ 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