diff --git a/include/xlnt/utils/numeric.hpp b/include/xlnt/utils/numeric.hpp
index c2ade2e6..1f6c182a 100644
--- a/include/xlnt/utils/numeric.hpp
+++ b/include/xlnt/utils/numeric.hpp
@@ -27,6 +27,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cmath>
+#include <cstddef>
 #include <limits>
 #include <sstream>
 #include <type_traits>