diff --git a/data_safe_haven/external/interface/pulumi_account.py b/data_safe_haven/external/interface/pulumi_account.py
index 4db66c52c8..0a240749f4 100644
--- a/data_safe_haven/external/interface/pulumi_account.py
+++ b/data_safe_haven/external/interface/pulumi_account.py
@@ -1,5 +1,6 @@
 """Manage Pulumi accounts"""
 
+import sys
 from shutil import which
 from typing import Any
 
@@ -39,5 +40,6 @@ def env(self) -> dict[str, Any]:
                 "AZURE_STORAGE_ACCOUNT": self.storage_account_name,
                 "AZURE_STORAGE_KEY": str(storage_account_keys[0].value),
                 "AZURE_KEYVAULT_AUTH_VIA_CLI": "true",
+                "PULUMI_PYTHON_CMD": sys.executable,
             }
         return self._env