diff --git a/mm_io.cpp b/mm_io.cpp
index c223e960d..e0cb38934 100644
--- a/mm_io.cpp
+++ b/mm_io.cpp
@@ -272,6 +272,18 @@ string mm_io_c::getline() {
 
 #endif
 
+size_t mm_io_c::writeline_unix_newlines(const char *s) {
+  int i;
+  size_t bytes_written;
+
+  bytes_written = 0;
+  for (i = 0; i < strlen(s); i++)
+    if (s[i] != '\r')
+      bytes_written += write(&s[i], 1);
+
+  return bytes_written;
+}
+
 /*
  * Dummy class for output to /dev/null. Needed for two pass stuff.
  */
diff --git a/mm_io.h b/mm_io.h
index c521911e2..40377329b 100644
--- a/mm_io.h
+++ b/mm_io.h
@@ -48,6 +48,7 @@ public:
   virtual bool eof();
   virtual char *gets(char *buffer, size_t max_size);
   virtual string getline();
+  virtual size_t writeline_unix_newlines(const char *s);
 };
 
 class mm_null_io_c: public mm_io_c {