diff --git a/fmt/parasplit.rs b/fmt/parasplit.rs
index 17f75bd0dac..76435868cf1 100644
--- a/fmt/parasplit.rs
+++ b/fmt/parasplit.rs
@@ -384,6 +384,11 @@ impl<'a> Iterator<Result<Paragraph,String>> for ParagraphStream<'a> {
             }
 
             pLines.push(self.lines.next().unwrap().get_fileline().line);
+
+            // when we're in split-only mode, we never join lines, so stop here
+            if self.opts.split_only {
+                break;
+            }
         }
 
         // if this was a mail header, then the next line can be detected as one. Otherwise, it cannot.