diff --git a/libvips/resample/reduceh.cpp b/libvips/resample/reduceh.cpp
index 9a1425df..6372ce41 100644
--- a/libvips/resample/reduceh.cpp
+++ b/libvips/resample/reduceh.cpp
@@ -38,8 +38,8 @@
  */
 
 /*
- */
 #define DEBUG
+ */
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>