diff --git a/bench_runner/scripts/run_benchmarks.py b/bench_runner/scripts/run_benchmarks.py
index a5db8884..01a3ad66 100644
--- a/bench_runner/scripts/run_benchmarks.py
+++ b/bench_runner/scripts/run_benchmarks.py
@@ -34,6 +34,7 @@
 )
 # Environment variables that control the execution of CPython
 ENV_VARS = ["PYTHON_JIT", "PYPERF_PERF_RECORD_EXTRA_OPTS"]
+LOOPS_FILE_ENV_VAR = "PYPERFORMANCE_LOOPS_FILE"
 
 
 class NoBenchmarkError(Exception):
@@ -82,6 +83,10 @@ def run_benchmarks(
     if extra_args is None:
         extra_args = []
 
+    if loops_file := os.environ.get(LOOPS_FILE_ENV_VAR):
+        extra_args.append("--same-loops")
+        extra_args.append(loops_file)
+
     if affinity := os.environ.get("CPU_AFFINITY"):
         extra_args.append(f"--affinity={affinity}")
 
@@ -133,7 +138,12 @@ def collect_pystats(
 
     all_benchmarks = get_benchmark_names(benchmarks)
 
-    extra_args = ["--same-loops", "loops.json", "--hook", "pystats"]
+    # Default to loops.json if not explicitly set, like before the
+    # environment variable was added.
+    if LOOPS_FILE_ENV_VAR not in os.environ:
+        os.environ[LOOPS_FILE_ENV_VAR] = "loops.json"
+
+    extra_args = ["--hook", "pystats"]
 
     if flags is None:
         flags = []