diff --git a/simplematrixbotlib/config.py b/simplematrixbotlib/config.py
index dda852e..5902730 100644
--- a/simplematrixbotlib/config.py
+++ b/simplematrixbotlib/config.py
@@ -1,29 +1,24 @@
 from dataclasses import dataclass, field
 import toml
 import re
-from typing import Set, Union
+from typing import Set
 
 
 @dataclass
 class Config:
     _join_on_invite: bool = True
     _allowlist: Set[re.Pattern] = field(
-        default_factory=set)  #TODO: default to bot's homeserver
+        default_factory=set)  # TODO: default to bot's homeserver
     _blocklist: Set[re.Pattern] = field(default_factory=set)
 
-    def _check_set_regex(self,
-                         value: Set[str]) -> Union[Set[re.Pattern], None]:
-        new_list = set()
+    @staticmethod
+    def _check_set_regex(value: Set[str]):
+        """Checks if the patterns in value are valid or throws an error"""
         for v in value:
             try:
-                tmp = re.compile(v)
+                re.compile(v)  # Fails for invalid regex
             except re.error:
-                print(
-                    f"{v} is not a valid regular expression. Ignoring your list update."
-                )
-                return None
-            new_list.add(tmp)
-        return new_list
+                raise re.error(f"{v} is not a valid regex.")
 
     def _load_config_dict(self, config_dict: dict) -> None:
         for key, value in config_dict.items():
@@ -80,34 +75,32 @@ def allowlist(self) -> Set[re.Pattern]:
 
     @allowlist.setter
     def allowlist(self, value: Set[str]) -> None:
-        checked = self._check_set_regex(value)
-        if checked is None:
-            return
-        self._allowlist = checked
+        self._check_set_regex(value)
+        self._allowlist = value
 
-    def add_allowlist(self, value: Set[str]) -> None:
+    def add_allowlist(self, value: Set[str]):
         """
+        Adds all regex to the allowlist if valid, else throws error
+
         Parameters
         ----------
         value : Set[str]
             A set of strings which represent Matrix IDs or a regular expression matching Matrix IDs to be added to allowlist.
         """
-        checked = self._check_set_regex(value)
-        if checked is None:
-            return
-        self._allowlist = self._allowlist.union(checked)
+        self._check_set_regex(value)
+        self._allowlist = self._allowlist.union(value)
 
-    def remove_allowlist(self, value: Set[str]) -> None:
+    def remove_allowlist(self, value: Set[str]):
         """
+        Removes all in the value set from the allowlist or throws an error
+
         Parameters
         ----------
         value : Set[str]
             A set of strings which represent Matrix IDs or a regular expression matching Matrix IDs to be removed from allowlist.
         """
-        checked = self._check_set_regex(value)
-        if checked is None:
-            return
-        self._allowlist = self._allowlist - checked
+        self._check_set_regex(value)
+        self._allowlist = self._allowlist - value
 
     @property
     def blocklist(self) -> Set[re.Pattern]:
@@ -122,10 +115,8 @@ def blocklist(self) -> Set[re.Pattern]:
 
     @blocklist.setter
     def blocklist(self, value: Set[str]) -> None:
-        checked = self._check_set_regex(value)
-        if checked is None:
-            return
-        self._blocklist = checked
+        self._check_set_regex(value)
+        self._blocklist = value
 
     def add_blocklist(self, value: Set[str]) -> None:
         """
@@ -134,10 +125,8 @@ def add_blocklist(self, value: Set[str]) -> None:
         value : Set[str]
             A set of strings which represent Matrix IDs or a regular expression matching Matrix IDs to be added to blocklist.
         """
-        checked = self._check_set_regex(value)
-        if checked is None:
-            return
-        self._blocklist = self._blocklist.union(checked)
+        self._check_set_regex(value)
+        self._blocklist = self._blocklist.union(value)
 
     def remove_blocklist(self, value: Set[str]) -> None:
         """
@@ -146,7 +135,5 @@ def remove_blocklist(self, value: Set[str]) -> None:
         value : Set[str]
             A set of strings which represent Matrix IDs or a regular expression matching Matrix IDs to be removed from blocklist.
         """
-        checked = self._check_set_regex(value)
-        if checked is None:
-            return
-        self._blocklist = self._blocklist - checked
+        self._check_set_regex(value)
+        self._blocklist = self._blocklist - value
diff --git a/tests/config/sample_config_files/config5.toml b/tests/config/sample_config_files/config5.toml
new file mode 100644
index 0000000..e0be816
--- /dev/null
+++ b/tests/config/sample_config_files/config5.toml
@@ -0,0 +1,3 @@
+[simplematrixbotlib.config]
+allowlist = ["[."]
+blocklist = ["@test2:example\\.org"]
diff --git a/tests/config/test_config.py b/tests/config/test_config.py
index ac42796..8adba1d 100644
--- a/tests/config/test_config.py
+++ b/tests/config/test_config.py
@@ -69,3 +69,14 @@ def test_manual_set():
     assert config.blocklist == set(map(re.compile, ['@test:matrix\\.org']))
     config.blocklist = {'*:example\\.org'}
     assert config.blocklist == set(map(re.compile, ['@test:matrix\\.org']))
+
+
+def test_botlib():
+    config = botlib.Config()
+    with pytest.raises(re.error):
+        config._check_set_regex(set(r"[."))
+    # Valid patterns
+    config._check_set_regex(set(r"@testuser:example.org"))
+
+    with pytest.raises(re.error):
+        config.load_toml(os.path.join(sample_config_path, 'config5.toml'))