diff --git a/var/spack/repos/builtin/packages/pixman/package.py b/var/spack/repos/builtin/packages/pixman/package.py
index 48c27e66399..5cbc9b94988 100644
--- a/var/spack/repos/builtin/packages/pixman/package.py
+++ b/var/spack/repos/builtin/packages/pixman/package.py
@@ -27,7 +27,7 @@ class Pixman(AutotoolsPackage):
     # __builtin_shuffle was removed in clang 5.0.
     # From version 9.1 apple-clang is based on clang 5.0.
     # Patch is obtained from above link.
-    patch('clang.patch', when='%clang@9.1.0-apple:')
+    patch('clang.patch', when='@0.34%clang@9.1.0-apple:')
 
     @run_before('build')
     def patch_config_h_for_intel(self):