diff --git a/var/spack/repos/builtin/packages/py-torch/package.py b/var/spack/repos/builtin/packages/py-torch/package.py
index 9af10cb65a3..2e1631fa027 100644
--- a/var/spack/repos/builtin/packages/py-torch/package.py
+++ b/var/spack/repos/builtin/packages/py-torch/package.py
@@ -526,6 +526,7 @@ def enable_or_disable(variant, keyword="USE", var=None):
 
         enable_or_disable("cuda")
         if "+cuda" in self.spec:
+            env.set("CUDA_TOOLKIT_ROOT_DIR", self.spec["cuda"].prefix)  # Linux/macOS
             env.set("CUDA_HOME", self.spec["cuda"].prefix)  # Linux/macOS
             env.set("CUDA_PATH", self.spec["cuda"].prefix)  # Windows
             self.torch_cuda_arch_list(env)