diff --git a/septentrion/runner.py b/septentrion/runner.py
index 3c12c7d..1a65fd8 100644
--- a/septentrion/runner.py
+++ b/septentrion/runner.py
@@ -38,7 +38,7 @@ def _env(self):
             "PGUSER": self.settings.USERNAME,
             "PGPASSWORD": self.settings.PASSWORD,
         }
-        return {key: value for key, value in environment.items() if value}
+        return {key: str(value) for key, value in environment.items() if value}
 
     def _run_simple(self):
 
diff --git a/tests/integration/test_runner.py b/tests/integration/test_runner.py
index c6aa5ca..fba4c38 100644
--- a/tests/integration/test_runner.py
+++ b/tests/integration/test_runner.py
@@ -58,6 +58,18 @@ def test_run_psql_not_found(run_script, env):
     )
 
 
+def test_run_integer_in_settings(db, settings_factory, env, tmp_path):
+    settings = settings_factory(**db)
+    # settings are noew stringified to prevent subprocess.run
+    # crashing while building the appropriate command line.
+    settings.PORT = 5432
+    path = tmp_path / "script.sql"
+    path.write_text("SELECT 1;")
+    with io.open(path, "r", encoding="utf8") as f:
+        script = Script(settings, f, path)
+        script.run()
+
+
 def test_run_with_meta_loop(db, settings_factory, run_script):
     settings = settings_factory(**db)