diff --git a/include/mapnik/util/char_array_buffer.hpp b/include/mapnik/util/char_array_buffer.hpp
index 894aa83b9..0acb5f4dd 100644
--- a/include/mapnik/util/char_array_buffer.hpp
+++ b/include/mapnik/util/char_array_buffer.hpp
@@ -24,6 +24,7 @@
 #define MAPNIK_UTIL_CHAR_ARRAY_BUFFER_HPP
 
 #include <streambuf>
+#include <algorithm>
 
 namespace mapnik { namespace util {
 
diff --git a/src/webp_reader.cpp b/src/webp_reader.cpp
index 8a806d0a1..095d3b004 100644
--- a/src/webp_reader.cpp
+++ b/src/webp_reader.cpp
@@ -39,6 +39,7 @@ MAPNIK_DISABLE_WARNING_POP
 // stl
 #include <fstream>
 #include <memory>
+#include <algorithm>
 
 namespace mapnik
 {