diff --git a/inputremapper/injection/macros/parse.py b/inputremapper/injection/macros/parse.py
index 71f4f202..68ac5a74 100644
--- a/inputremapper/injection/macros/parse.py
+++ b/inputremapper/injection/macros/parse.py
@@ -421,6 +421,12 @@ def parse(macro, context=None, return_errors=False):
 
     try:
         macro_object = _parse_recurse(macro, context)
+
+        if not isinstance(macro_object, Macro):
+            # someone put a single parameter like a string into this function, and
+            # it was most likely returned without modification. Not a macro
+            raise ValueError("The provided code was not a macro")
+
         return macro_object if not return_errors else None
     except Exception as error:
         logger.error('Failed to parse macro "%s": %s', macro, error.__repr__())
diff --git a/tests/unit/test_macros.py b/tests/unit/test_macros.py
index ce6c9149..32b741cb 100644
--- a/tests/unit/test_macros.py
+++ b/tests/unit/test_macros.py
@@ -360,6 +360,10 @@ class TestMacros(MacroTestBase):
         self.assertIsNone(parse("r(a, k(b))", self.context))
         self.assertIsNone(parse("m(a, b)", self.context))
 
+        # passing a string parameter. This is not a macro, even though
+        # it might look like it without the string quotes.
+        self.assertIsNone(parse('"m(a, b)"', self.context))
+
     async def test_0(self):
         macro = parse("k(1)", self.context)
         one_code = system_mapping.get("1")