diff --git a/src/pipeline.cc b/src/pipeline.cc
index f468a175..8b513f65 100644
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -3,6 +3,7 @@
 #include <tuple>
 #include <utility>
 #include <memory>
+#include <numeric>
 
 #include <vips/vips8>