diff --git a/var/spack/repos/builtin/packages/py-pillow-simd/package.py b/var/spack/repos/builtin/packages/py-pillow-simd/package.py
index 03d1abece60..0f1944aeba8 100644
--- a/var/spack/repos/builtin/packages/py-pillow-simd/package.py
+++ b/var/spack/repos/builtin/packages/py-pillow-simd/package.py
@@ -21,3 +21,5 @@ class PyPillowSimd(PyPillowBase):
 
     for ver in ['6.2.2.post1', '7.0.0.post3', '9.0.0.post1']:
         provides('pil@' + ver, when='@' + ver)
+
+    conflicts('target=aarch64:')