diff --git a/solanaceae/ngc_ft1/rcv_buf.hpp b/solanaceae/ngc_ft1/rcv_buf.hpp
index 1ac7187..481c366 100644
--- a/solanaceae/ngc_ft1/rcv_buf.hpp
+++ b/solanaceae/ngc_ft1/rcv_buf.hpp
@@ -4,6 +4,7 @@
 #include <map>
 #include <deque>
 #include <cstdint>
+#include <cstddef>
 
 struct RecvSequenceBuffer {
 	struct RSBEntry {
diff --git a/solanaceae/ngc_ft1/snd_buf.hpp b/solanaceae/ngc_ft1/snd_buf.hpp
index 416f051..ca67753 100644
--- a/solanaceae/ngc_ft1/snd_buf.hpp
+++ b/solanaceae/ngc_ft1/snd_buf.hpp
@@ -3,6 +3,7 @@
 #include <vector>
 #include <map>
 #include <cstdint>
+#include <cstddef>
 
 struct SendSequenceBuffer {
 	struct SSBEntry {