diff --git a/src/calibre/ebooks/txt/input.py b/src/calibre/ebooks/txt/input.py
index 75bafc7cef..674277fc41 100644
--- a/src/calibre/ebooks/txt/input.py
+++ b/src/calibre/ebooks/txt/input.py
@@ -58,6 +58,7 @@ class TXTInput(InputFormatPlugin):
                 accelerators):
         self.log = log
         log.debug('Reading text from file...')
+        length = 0
 
         txt = stream.read()
 
@@ -109,11 +110,12 @@ class TXTInput(InputFormatPlugin):
         # Reformat paragraphs to block formatting based on the detected type.
         # We don't check for block because the processor assumes block.
         # single and print at transformed to block for processing.
-        if options.paragraph_type == 'single' or options.paragraph_type == 'unformatted':
+        if options.paragraph_type == 'single':
             txt = separate_paragraphs_single_line(txt)
         elif options.paragraph_type == 'print':
             txt = separate_paragraphs_print_formatted(txt)
         elif options.paragraph_type == 'unformatted':
+            print "unwrapping lines using heuristics"
             from calibre.ebooks.conversion.utils import HeuristicProcessor
             # unwrap lines based on punctuation
             docanalysis = DocAnalysis('txt', txt)
@@ -123,7 +125,8 @@ class TXTInput(InputFormatPlugin):
 
         if getattr(options, 'enable_heuristics', False) and getattr(options, 'dehyphenate', False):
             docanalysis = DocAnalysis('txt', txt)
-            length = docanalysis.line_length(.5)
+            if not length:
+                length = docanalysis.line_length(.5)
             dehyphenator = Dehyphenator(options.verbose, log=self.log)
             txt = dehyphenator(txt,'txt', length)