diff --git a/var/spack/repos/builtin/packages/mgard/package.py b/var/spack/repos/builtin/packages/mgard/package.py
index 411dd0c9b9..24ac8d25db 100644
--- a/var/spack/repos/builtin/packages/mgard/package.py
+++ b/var/spack/repos/builtin/packages/mgard/package.py
@@ -53,6 +53,9 @@ class Mgard(CMakePackage, CudaPackage):
     depends_on("cmake@3.19:", type="build")
     depends_on("nvcomp@2.2.0:", when="@2022-11-18:+cuda")
     depends_on("nvcomp@2.0.2", when="@:2021-11-12+cuda")
+    with when("+openmp"):
+        depends_on("llvm-openmp", when="%apple-clang")
+
     conflicts("cuda_arch=none", when="+cuda")
     conflicts(
         "~cuda", when="@2021-11-12", msg="without cuda MGARD@2021-11-12 has undefined symbols"