diff --git a/flux_local/tool/selector.py b/flux_local/tool/selector.py
index f5c4c407..8c7456f8 100644
--- a/flux_local/tool/selector.py
+++ b/flux_local/tool/selector.py
@@ -30,6 +30,8 @@ def __call__(
         option_string: str | None = None,
     ) -> None:
         values = values.split(",")
+        if not values[0]:
+            return
         try:
             source = git_repo.Source.from_str(values[0])
         except ValueError:
diff --git a/tests/tool/testdata/diff_ks_yaml_empty_sources.yaml b/tests/tool/testdata/diff_ks_yaml_empty_sources.yaml
new file mode 100644
index 00000000..87fd2253
--- /dev/null
+++ b/tests/tool/testdata/diff_ks_yaml_empty_sources.yaml
@@ -0,0 +1,10 @@
+args:
+- diff
+- ks
+- apps
+- --path
+- tests/testdata/cluster/
+- -o
+- yaml
+- --sources
+- ""