diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index 89ed579f55..bab8b0d4b3 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -12,6 +12,7 @@
 
 #include <inttypes.h>
 #include <stdbool.h>
+#include <stddef.h>
 
 /*
  * For best performance, build the plugin with -fvisibility=hidden so that