diff --git a/src/ert/resources/forward_models/run_reservoirsimulator.py b/src/ert/resources/forward_models/run_reservoirsimulator.py
index a6247dcf8ab..983749342ee 100755
--- a/src/ert/resources/forward_models/run_reservoirsimulator.py
+++ b/src/ert/resources/forward_models/run_reservoirsimulator.py
@@ -155,7 +155,7 @@ def __init__(
         self.summary_conversion: bool = summary_conversion
 
         self.bypass_flowrun: bool = False
-        self.forwarded_args: list[str] = forwarded_args or []
+        self.forwarded_args: list[str] = " ".join(forwarded_args or []).split()
 
         runner_abspath: str | Path | None = None
         if simulator in {"eclipse", "e300"}:
diff --git a/tests/ert/unit_tests/resources/test_run_reservoirsimulator.py b/tests/ert/unit_tests/resources/test_run_reservoirsimulator.py
index 2f7d054e698..ab26c7b83b3 100644
--- a/tests/ert/unit_tests/resources/test_run_reservoirsimulator.py
+++ b/tests/ert/unit_tests/resources/test_run_reservoirsimulator.py
@@ -161,7 +161,7 @@ def slow_smry_writer():
 
 @pytest.mark.parametrize("simulator", ["eclipse", "e300", "flow"])
 @pytest.mark.usefixtures("use_tmpdir")
-def test_runner_will_forward_unknown_arguments_to_eclrun(monkeypatch, simulator):
+def test_runner_will_forward_unknown_arguments(monkeypatch, simulator):
     eclrun_bin = Path("bin/eclrun")
     eclrun_bin.parent.mkdir()
     eclrun_bin.write_text("#!/bin/sh\necho $@ > eclrun_args\nexit 0", encoding="utf-8")
@@ -184,3 +184,33 @@ def test_runner_will_forward_unknown_arguments_to_eclrun(monkeypatch, simulator)
     assert "--arbitrary_option_being_forwarded" in Path("eclrun_args").read_text(
         encoding="utf-8"
     )
+
+
+@pytest.mark.parametrize("simulator", ["eclipse", "e300", "flow"])
+@pytest.mark.usefixtures("use_tmpdir")
+def test_runner_will_forward_multiple_unknown_arguments(monkeypatch, simulator):
+    eclrun_bin = Path("bin/eclrun")
+    eclrun_bin.parent.mkdir()
+    eclrun_bin.write_text(
+        '#!/bin/sh\nfor arg in "$@"; do echo $arg >> eclrun_args; done\nexit 0',
+        encoding="utf-8",
+    )
+    eclrun_bin.chmod(eclrun_bin.stat().st_mode | stat.S_IEXEC)
+    shutil.copy(eclrun_bin, "bin/flowrun")
+    monkeypatch.setenv("PATH", f"bin:{os.environ['PATH']}")
+    Path("EIGHTCELLS.DATA").touch()
+    Path("EIGHTCELLS.PRT").write_text("Errors 0\nBugs 0", encoding="utf-8")
+
+    run_reservoirsimulator.run_reservoirsimulator(
+        [
+            simulator,
+            "EIGHTCELLS.DATA",
+            "--version",
+            "2019.3",
+            "--first-option --second-option",
+        ]
+    )
+
+    assert "--first-option\n--second-option" in Path("eclrun_args").read_text(
+        encoding="utf-8"
+    )