diff --git a/lib/galaxy/tool_util/deps/conda_util.py b/lib/galaxy/tool_util/deps/conda_util.py
index 8bead7148a5d..ccc8cf2da06d 100644
--- a/lib/galaxy/tool_util/deps/conda_util.py
+++ b/lib/galaxy/tool_util/deps/conda_util.py
@@ -425,7 +425,7 @@ class CondaTarget:
     def __init__(
         self, package: str, version: Optional[str] = None, build: Optional[str] = None, channel: Optional[str] = None
     ) -> None:
-        if SHELL_UNSAFE_PATTERN.search(package) is not None:
+        if SHELL_UNSAFE_PATTERN.search(package) is not None or not package:
             raise ValueError(f"Invalid package [{package}] encountered.")
         self.capitalized_package = package
         self.package = package.lower()
diff --git a/lib/galaxy/tool_util/deps/mulled/mulled_build.py b/lib/galaxy/tool_util/deps/mulled/mulled_build.py
index be956c84a8b9..422ac0a0b605 100644
--- a/lib/galaxy/tool_util/deps/mulled/mulled_build.py
+++ b/lib/galaxy/tool_util/deps/mulled/mulled_build.py
@@ -527,8 +527,8 @@ def add_single_image_arguments(parser):
     )
 
 
-def target_str_to_targets(targets_raw):
-    def parse_target(target_str):
+def target_str_to_targets(targets_raw: str) -> List[CondaTarget]:
+    def parse_target(target_str: str) -> CondaTarget:
         if "=" in target_str:
             package_name, version = target_str.split("=", 1)
             build = None
@@ -541,8 +541,10 @@ def parse_target(target_str):
             target = build_target(target_str)
         return target
 
-    targets = [parse_target(_) for _ in targets_raw.split(",")]
-    return targets
+    if targets_raw.strip() == "":
+        return []
+    else:
+        return [parse_target(_) for _ in targets_raw.split(",")]
 
 
 def args_to_mull_targets_kwds(args):