diff --git a/lib/line_wrapper.coffee b/lib/line_wrapper.coffee
index a64aa02..d68300a 100644
--- a/lib/line_wrapper.coffee
+++ b/lib/line_wrapper.coffee
@@ -74,7 +74,7 @@ class LineWrapper extends EventEmitter
         while word.length
           # fit as much of the word as possible into the space we have
           l = word.length
-          while w > @spaceLeft
+          while w > @spaceLeft and l > 0
             w = @wordWidth word.slice(0, --l)
             
           # send a required break unless this is the last piece