diff --git a/src/calibre/ebooks/conversion/plugins/snb_input.py b/src/calibre/ebooks/conversion/plugins/snb_input.py
index 75275dbf34..007adea1b9 100644
--- a/src/calibre/ebooks/conversion/plugins/snb_input.py
+++ b/src/calibre/ebooks/conversion/plugins/snb_input.py
@@ -45,7 +45,7 @@ class SNBInput(InputFormatPlugin):
         except:
             raise ValueError("Invalid SNB file")
         if not snbFile.IsValid():
-            log.debug("Invaild SNB file")
+            log.debug("Invalid SNB file")
             raise ValueError("Invalid SNB file")
         log.debug("Handle meta data ...")
         from calibre.ebooks.conversion.plumber import create_oebbook