diff --git a/C4/Koha.pm b/C4/Koha.pm
index 1061a78a80..8dd513d86e 100644
--- a/C4/Koha.pm
+++ b/C4/Koha.pm
@@ -1640,6 +1640,9 @@ sub GetVariationsOfISBN {
     push( @isbns, NormalizeISBN({ isbn => $isbn, format => 'ISBN-10', strip_hyphens => 1 }) );
     push( @isbns, NormalizeISBN({ isbn => $isbn, format => 'ISBN-13', strip_hyphens => 1 }) );
 
+    # Strip out any "empty" strings from the array
+    @isbns = grep { /\S/ } @isbns;
+
     return wantarray ? @isbns : join( " | ", @isbns );
 }