diff --git a/batch/inference_job_launcher.py b/batch/inference_job_launcher.py
index efc3ec76f..94e628e51 100755
--- a/batch/inference_job_launcher.py
+++ b/batch/inference_job_launcher.py
@@ -712,7 +712,7 @@ def launch(self, job_name, config_file, seir_modifiers_scenarios, outcome_modifi
             cur_env_vars = base_env_vars.copy()
             cur_env_vars.append({"name": "FLEPI_SEIR_SCENARIOS", "value": s})
             cur_env_vars.append({"name": "FLEPI_OUTCOME_SCENARIOS", "value": d})
-            cur_env_vars.append({"name": "FLEPI_PREFIX", "value": f"{config['name']}/{s}/{d}"})
+            cur_env_vars.append({"name": "FLEPI_PREFIX", "value": f"{config['name']}_{s}_{d}"})
             cur_env_vars.append({"name": "FLEPI_BLOCK_INDEX", "value": "1"})
             cur_env_vars.append({"name": "FLEPI_RUN_INDEX", "value": f"{self.run_id}"})
             if not (self.restart_from_location is None):