diff --git a/bookwyrm/book_search.py b/bookwyrm/book_search.py
index 29c48c936..4ea4c14a8 100644
--- a/bookwyrm/book_search.py
+++ b/bookwyrm/book_search.py
@@ -32,7 +32,7 @@ def isbn_search(query):
         return []
     # Up-case the ISBN string to ensure any 'X' check-digit is correct
     # If the ISBN has only 9 characters, prepend missing zero
-    query = query.upper().rjust(10, '0')
+    query = query.strip().upper().rjust(10, '0')
     filters = [{f: query} for f in ["isbn_10", "isbn_13"]]
     results = models.Edition.objects.filter(
         reduce(operator.or_, (Q(**f) for f in filters))
diff --git a/bookwyrm/connectors/abstract_connector.py b/bookwyrm/connectors/abstract_connector.py
index 87cae00c0..32559a307 100644
--- a/bookwyrm/connectors/abstract_connector.py
+++ b/bookwyrm/connectors/abstract_connector.py
@@ -44,9 +44,8 @@ class AbstractMinimalConnector(ABC):
         if maybe_isbn(query) and self.isbn_search_url and self.isbn_search_url != "":
             # Up-case the ISBN string to ensure any 'X' check-digit is correct
             # If the ISBN has only 9 characters, prepend missing zero
-            query = query.upper().rjust(10, '0')
-            return f"{self.isbn_search_url}{query}"
-
+            normalized_query = query.strip().upper().rjust(10, '0')
+            return f"{self.isbn_search_url}{normalized_query}"
         # NOTE: previously, we tried searching isbn and if that produces no results,
         # searched as free text. This, instead, only searches isbn if it's isbn-y
         return f"{self.search_url}{query}"