diff --git a/src/libcamera/converter/converter_v4l2_m2m.cpp b/src/libcamera/converter/converter_v4l2_m2m.cpp
index ee05b798..0ce7a7a6 100644
--- a/src/libcamera/converter/converter_v4l2_m2m.cpp
+++ b/src/libcamera/converter/converter_v4l2_m2m.cpp
@@ -10,6 +10,7 @@
 
 #include <algorithm>
 #include <limits.h>
+#include <set>
 
 #include <libcamera/base/log.h>
 #include <libcamera/base/signal.h>