diff --git a/pymispgalaxies/api.py b/pymispgalaxies/api.py
index 3aafbe2..4f938fc 100644
--- a/pymispgalaxies/api.py
+++ b/pymispgalaxies/api.py
@@ -8,7 +8,12 @@ import sys
 from collections.abc import Mapping
 from glob import glob
 import re
-from typing import List, Dict, Optional, Any, Tuple, Iterator
+from typing import List, Dict, Optional, Any, Tuple, Iterator, overload, Union
+
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
 
 try:
     import jsonschema  # type: ignore
@@ -225,7 +230,14 @@ class Cluster(Mapping):  # type: ignore
                     raise PyMISPGalaxiesError("Duplicate value ({}) in cluster: {}".format(new_cluster_value.value, self.name))
             self.cluster_values[new_cluster_value.value] = new_cluster_value
 
-    def search(self, query: str, return_tags: bool=False) -> List[str]:
+    @overload
+    def search(self, query: str, return_tags: Literal[False]=False) -> List[ClusterValue]: ...
+    @overload
+    def search(self, query: str, return_tags: Literal[True]) -> List[str]: ...
+    @overload
+    def search(self, query: str, return_tags: bool) -> Union[List[ClusterValue], List[str]]: ...
+
+    def search(self, query: str, return_tags: bool=False) -> Union[List[ClusterValue], List[str]]:
         matching = []
         for v in self.values():
             if [s for s in v.searchable if query.lower() in s.lower()]: