diff --git a/src/imcflibs/imagej/omerotools.py b/src/imcflibs/imagej/omerotools.py
index 7dad756f..856c5a57 100644
--- a/src/imcflibs/imagej/omerotools.py
+++ b/src/imcflibs/imagej/omerotools.py
@@ -57,6 +57,12 @@ def parse_url(client, omero_str):
     >>> for wrapper in img_wrappers:
     >>>    imp = wpr.toImagePlus(client)
     """
+    if not str(omero_str).strip():
+        raise ValueError("No OMERO link or image ID provided.")
+
+    # Sanitize the string
+    omero_str = omero_str.strip()
+
     image_ids = []
     dataset_ids = []
     image_wpr_list = []