diff --git a/freqtrade/strategy/hyper.py b/freqtrade/strategy/hyper.py
index 847aac102..123600c55 100644
--- a/freqtrade/strategy/hyper.py
+++ b/freqtrade/strategy/hyper.py
@@ -192,6 +192,10 @@ def detect_all_parameters(
             raise OperationalException(
                 f"Conflicting parameter space for {attr_name}: {auto_category} vs {attr.category}."
             )
+        if attr.category in ("all", "default") or attr.category.isidentifier() is False:
+            raise OperationalException(
+                f"'{attr.category}' is not a valid space. Parameter: {attr_name}."
+            )
         attr.name = attr_name
         result[attr.category][attr_name] = attr
     return result
diff --git a/tests/strategy/test_interface.py b/tests/strategy/test_interface.py
index bf422d0ec..5f3c11821 100644
--- a/tests/strategy/test_interface.py
+++ b/tests/strategy/test_interface.py
@@ -952,6 +952,7 @@ def test_auto_hyperopt_interface(default_conf):
 
     with pytest.raises(OperationalException, match=r"Conflicting parameter space.*"):
         detect_all_parameters(strategy.__class__)
+    del strategy.__class__.sell_rsi
 
     strategy.__class__.exit22_rsi = IntParameter([0, 10], default=5)
 
@@ -960,6 +961,20 @@ def test_auto_hyperopt_interface(default_conf):
     ):
         detect_all_parameters(strategy.__class__)
 
+    # Invalid parameter space
+    strategy.__class__.exit22_rsi = IntParameter([0, 10], default=5, space="all")
+    with pytest.raises(
+        OperationalException, match=r"'all' is not a valid space\. Parameter: exit22_rsi\."
+    ):
+        detect_all_parameters(strategy.__class__)
+
+    strategy.__class__.exit22_rsi = IntParameter([0, 10], default=5, space="hello:world:22")
+    with pytest.raises(
+        OperationalException,
+        match=r"'hello:world:22' is not a valid space\. Parameter: exit22_rsi\.",
+    ):
+        detect_all_parameters(strategy.__class__)
+
 
 def test_auto_hyperopt_interface_loadparams(default_conf, mocker, caplog):
     default_conf.update({"strategy": "HyperoptableStrategy"})