diff --git a/TODO b/TODO
index 4d102e7f..3f6450a6 100644
--- a/TODO
+++ b/TODO
@@ -5,6 +5,7 @@
 
   14.04 is orc-0.4.18, there must have been a change
 
+  nope, still broken with 0.4.11
 
 
 
diff --git a/libvips/arithmetic/hough_line.c b/libvips/arithmetic/hough_line.c
index 6fac6e2f..eaa5b8bd 100644
--- a/libvips/arithmetic/hough_line.c
+++ b/libvips/arithmetic/hough_line.c
@@ -37,6 +37,7 @@
 #include <vips/intl.h>
 
 #include <string.h>
+#include <math.h>
 
 #include <vips/vips.h>