diff --git a/src/calibre/devices/kindle/apnx.py b/src/calibre/devices/kindle/apnx.py
index 8e8773e058..19d34c0a5f 100644
--- a/src/calibre/devices/kindle/apnx.py
+++ b/src/calibre/devices/kindle/apnx.py
@@ -62,9 +62,9 @@ def write_apnx(self, mobi_file_path, apnx_path, method=None, page_count=0):
             pages = self.get_pages_exact(mobi_file_path, page_count)
         else:
             try:
-                if method='accurate':
+                if method == 'accurate':
                     pages = self.get_pages_accurate(mobi_file_path)
-                elif method='pagebreak':
+                elif method == 'pagebreak':
                     pages = self.get_pages_pagebreak_tag(mobi_file_path)
                 else:
                     raise('no valid accurate method chosen use fast')