diff --git a/src/calibre/ebooks/mobi/reader.py b/src/calibre/ebooks/mobi/reader.py
index 2260b981b6..f2856da4cf 100644
--- a/src/calibre/ebooks/mobi/reader.py
+++ b/src/calibre/ebooks/mobi/reader.py
@@ -127,7 +127,6 @@ class BookHeader(object):
             self.length, self.type, self.codepage, self.unique_id, \
                 self.version = struct.unpack('>LLLLL', raw[20:40])
 
-
             try:
                 self.codec = {
                     1252: 'cp1252',
@@ -154,24 +153,31 @@ class BookHeader(object):
             sublangid = (langcode >> 10) & 0xFF
             self.language = main_language.get(langid, 'ENGLISH')
             self.sublanguage = sub_language.get(sublangid, 'NEUTRAL')
-            self.mobi_version = struct.unpack('>I', raw[0x68:0x6c])[0]
-            self.first_image_index = struct.unpack('>L', raw[0x6c:0x6c + 4])[0]
 
-            self.exth_flag, = struct.unpack('>L', raw[0x80:0x84])
-            self.exth = None
-            if not isinstance(self.title, unicode):
-                self.title = self.title.decode(self.codec, 'replace')
-            if self.exth_flag & 0x40:
-                try:
-                    self.exth = EXTHHeader(raw[16 + self.length:], self.codec, self.title)
-                    self.exth.mi.uid = self.unique_id
+            if ident == 'TEXTREAD':
+                self.mobi_version = 1
+                self.first_image_index = -1
+                self.exth_flag = 0
+                self.exth = None
+            else:
+                self.mobi_version = struct.unpack('>I', raw[0x68:0x6c])[0]
+                self.first_image_index = struct.unpack('>L', raw[0x6c:0x6c + 4])[0]
+                self.exth_flag, = struct.unpack('>L', raw[0x80:0x84])
+
+                self.exth = None
+                if not isinstance(self.title, unicode):
+                    self.title = self.title.decode(self.codec, 'replace')
+                if self.exth_flag & 0x40:
                     try:
-                        self.exth.mi.language = mobi2iana(langid, sublangid)
+                        self.exth = EXTHHeader(raw[16 + self.length:], self.codec, self.title)
+                        self.exth.mi.uid = self.unique_id
+                        try:
+                            self.exth.mi.language = mobi2iana(langid, sublangid)
+                        except:
+                            self.log.exception("'%s': Unknown language code" % getattr(stream, 'name', 'Unnamed stream'))
                     except:
-                        self.log.exception("'%s': Unknown language code" % getattr(stream, 'name', 'Unnamed stream'))
-                except:
-                    self.log.exception("'%s': Invalid EXTH header" % getattr(stream, 'name', 'Unnamed stream'))
-                    self.exth_flag = 0
+                        self.log.exception("'%s': Invalid EXTH header" % getattr(stream, 'name', 'Unnamed stream'))
+                        self.exth_flag = 0
 
 
 class MetadataHeader(BookHeader):