diff --git a/tests/conftest.py b/tests/conftest.py
index 2ece01ca4..6cfdcfc78 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -450,7 +450,7 @@ def do_yggdrasil_mods(opts, dont_exit=False):
         opts += ['-p', 'no:flaky']
         opts -= ['--reruns=2', '--reruns-delay=1', '--timeout=900']
         # TODO: Remove these once MPI debugged
-        opts += ['-svx']
+        prefix_pytest += ['-svx']
     # Continuous integration
     if options.ci and (not _on_mpi):
         setup_ci(opts)
diff --git a/utils/setup_test_env.py b/utils/setup_test_env.py
index 1aa47b4b5..b02d77f30 100644
--- a/utils/setup_test_env.py
+++ b/utils/setup_test_env.py
@@ -1213,7 +1213,7 @@ def build_conda_recipe(recipe='recipe', param=None,
     ]
     # Mamba index not available
     # cmds.append(f"{param.conda_exe} index {conda_idx}")
-    cmds.append("conda index {conda_idx}")
+    cmds.append(f"conda index {conda_idx}")
     if return_commands:
         return cmds
     if cmds: