--- a/filters/jpeg.cpp
+++ b/filters/jpeg.cpp
@@ -410,13 +410,13 @@
   cinfo_.image_height = ctx_.height ();
 
   jpeg_set_defaults (&cinfo_);
-  jpeg_set_quality  (&cinfo_, quality_, true);
+  jpeg_set_quality  (&cinfo_, quality_, TRUE);
 
   cinfo_.density_unit = 1;      // in dpi
   cinfo_.X_density = ctx_.x_resolution ();
   cinfo_.Y_density = ctx_.y_resolution ();
 
-  jpeg_start_compress (&cinfo_, true);
+  jpeg_start_compress (&cinfo_, TRUE);
 
   cache_ = new octet[ctx_.octets_per_line ()];
   cache_size_ = ctx_.octets_per_line ();
@@ -462,7 +462,7 @@
   dmgr_.next_output_byte = jbuf_ + (jbuf_size_ - n);
   dmgr_.free_in_buffer   = n;
 
-  return true;
+  return TRUE;
 }
 
 void
@@ -535,7 +535,7 @@
 
   //jpegデータの一部が分割されて送られてきても正常に動作するように変更
 
-  return false;
+  return FALSE;
 }
 
 void
@@ -580,7 +580,7 @@
 {
   if (!header_done_)
     {
-      if (JPEG_SUSPENDED == jpeg_read_header (&cinfo_, true))
+      if (JPEG_SUSPENDED == jpeg_read_header (&cinfo_, TRUE))
         {
           log::trace ("jpeg_read_header suspended");
           if (!reclaim_space ())