diff --git a/lib/galaxy/tool_util/deps/mulled/mulled_hash.py b/lib/galaxy/tool_util/deps/mulled/mulled_hash.py
index eca1da8536f4..a8cfeef3ae4e 100644
--- a/lib/galaxy/tool_util/deps/mulled/mulled_hash.py
+++ b/lib/galaxy/tool_util/deps/mulled/mulled_hash.py
@@ -7,6 +7,7 @@
 
     mulled-hash samtools=1.3.1,bedtools=2.22
 """
+from typing import Literal
 
 from ._cli import arg_parser
 from .mulled_build import target_str_to_targets
@@ -16,14 +17,14 @@
 )
 
 
-def _mulled_hash(hash, targets):
+def _mulled_hash(hash: Literal["v1", "v2"], targets_str: str):
     """
     >>> _mulled_hash(hash="v2", targets="samtools=1.3.1,bedtools=2.26.0")
     'mulled-v2-8186960447c5cb2faa697666dc1e6d919ad23f3e:a6419f25efff953fc505dbd5ee734856180bb619'
     >>> _mulled_hash(hash="v2", targets="samtools=1.3.1=h9071d68_10,bedtools=2.26.0=0")
     'mulled-v2-8186960447c5cb2faa697666dc1e6d919ad23f3e:a6419f25efff953fc505dbd5ee734856180bb619'
     """
-    targets = target_str_to_targets(targets)
+    targets = target_str_to_targets(targets_str)
     image_name = v2_image_name if hash == "v2" else v1_image_name
     return image_name(targets)