diff --git a/llvm17.spec b/llvm17.spec
index 4121f71..57d43e5 100644
--- a/llvm17.spec
+++ b/llvm17.spec
@@ -70,6 +70,7 @@ BuildRequires:  python38-devel
 BuildRequires:	sed
 BuildRequires:	tcl
 BuildRequires:	zip
+BuildRequires:  pkgconfig(x11)
 %if %{compile_apidox}
 BuildRequires:	doxygen
 %endif