diff --git a/src/caoscrawler/crawl.py b/src/caoscrawler/crawl.py
index 1b9b9e48d3f46d8638312a03e383105f14bcf87c..9a0e6ce560a4ccdc2caf80f4a5cc70736cde22f8 100644
--- a/src/caoscrawler/crawl.py
+++ b/src/caoscrawler/crawl.py
@@ -1286,7 +1286,9 @@ def crawler_main(crawled_directory_path: str,
         warnings.warn(DeprecationWarning("The prefix argument is deprecated and will be removed "
                                          "in the future. Please use `remove_prefix` instead."))
         if remove_prefix is not None:
-            raise ValueError("Please do not supply prefix argument. Only remove_prefix")
+            raise ValueError("Please do not supply the (deprecated) `prefix` and the "
+                             "`remove_prefix` argument at the same time. Only use "
+                             "`remove_prefix` instead.")
         remove_prefix = prefix
 
     if dry_run:
diff --git a/unittests/test_tool.py b/unittests/test_tool.py
index eb4350bd1b5adc29941b12e9d0de99991e143321..879bbe70f68bf78bc5f47bc3b64a4a82b4ae6cf9 100755
--- a/unittests/test_tool.py
+++ b/unittests/test_tool.py
@@ -976,3 +976,9 @@ def test_deprecated_prefix_option():
 
     with pytest.deprecated_call():
         crawler_main("./", rfp("scifolder_cfood.yml"), prefix="to/be/removed")
+
+    with raises(ValueError) as ve:
+        crawler_main("./", rfp("scifolder_cfood.yml"), prefix="to/be/removed",
+                     remove_prefix="to/be/removed")
+
+    assert "(deprecated) `prefix` and the `remove_prefix`" in str(ve.value)