diff --git a/src/subscript/field_statistics/field_statistics.py b/src/subscript/field_statistics/field_statistics.py
index 1d4952517..5b6bfa324 100644
--- a/src/subscript/field_statistics/field_statistics.py
+++ b/src/subscript/field_statistics/field_statistics.py
@@ -952,11 +952,11 @@ def generate_script(
 ERT_CONFIG_PATH = "{ert_config_path}"
 
 GLOBAL_VARIABLES_FILE  = \
-    ERT_CONFIG_PATH / Path("../../fmuconfig/output/global_variables.yml")
+    Path(ERT_CONFIG_PATH) / Path("../../fmuconfig/output/global_variables.yml")
 
-FIELD_STAT_CONFIG_FILE = "{field_stat_config_file}"
+FIELD_STAT_CONFIG_FILE = Path(ERT_CONFIG_PATH) / Path("{field_stat_config_file}")
 
-RESULT_PATH = "{result_path}"
+RESULT_PATH = Path("{result_path}")
 
 
 LABEL = "drogon"
@@ -981,7 +981,10 @@ def main():
     zone_code_names = field_stat["zone_code_names"]
     facies_per_zone = get_facies_per_zone(GLOBAL_VARIABLES_FILE)
     result_path = RESULT_PATH
-    zone_list= list(zone_code_names.values())
+    if "use_zones" in field_stat:
+        zone_list= field_stat["use_zones"]
+    else:
+        zone_list= list(zone_code_names.values())
     stat_list= ["mean", "stdev"]
     iter_list = field_stat["iterations"]
 
diff --git a/tests/test_field_statistics.py b/tests/test_field_statistics.py
index d073b2fae..91a14d181 100644
--- a/tests/test_field_statistics.py
+++ b/tests/test_field_statistics.py
@@ -881,7 +881,6 @@ def test_get_specification(
 )
 def test_main(tmp_path, config_file, config_dict, print_info=True):
     import subprocess
-    import sys
 
     # First make an ensemble to be used as testdata. This is based on the config_dict
     _, ens_path, result_path, ert_config_path, _ = make_test_case(tmp_path, config_dict)
@@ -892,18 +891,11 @@ def test_main(tmp_path, config_file, config_dict, print_info=True):
     result_path = ens_path / RESULT_PATH
 
     rms_load_script = result_path / RMS_LOAD_SCRIPT_NAME
+
     # Run the main script as a subprocess
-    script_name = Path(__file__).absolute().parent.parent / Path(
-        "src/subscript/field_statistics/field_statistics.py"
-    )
-    if print_info:
-        print(f"\nRun script:  {script_name}")
-    remove_file_path = result_path / Path("ertbox--*.roff")
-    subprocess.run(["rm", "-f", remove_file_path])
     subprocess.run(
         [
-            sys.executable,
-            script_name.as_posix(),
+            "field_statistics",
             "-c",
             config_path.as_posix(),
             "-p",