diff --git a/var/spack/repos/builtin/packages/mesa/package.py b/var/spack/repos/builtin/packages/mesa/package.py
index b07cfd59fd..7c8a4bfaa6 100644
--- a/var/spack/repos/builtin/packages/mesa/package.py
+++ b/var/spack/repos/builtin/packages/mesa/package.py
@@ -84,6 +84,8 @@ class Mesa(MesonPackage):
     # OpenGL ES requires OpenGL
     conflicts('~opengl +opengles')
 
+    # 'auto' needed when shared llvm is built
+    @when('^llvm~shared_libs')
     def patch(self):
         filter_file(
             r"_llvm_method = 'auto'",