diff --git a/src/filter/facebl0r/facebl0r.cpp b/src/filter/facebl0r/facebl0r.cpp
index 0e5c844..e45de6d 100644
--- a/src/filter/facebl0r/facebl0r.cpp
+++ b/src/filter/facebl0r/facebl0r.cpp
@@ -19,6 +19,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <opencv2/opencv.hpp>
+#include <opencv2/xobjdetect.hpp>
 #include "frei0r.hpp"
 #include "frei0r/math.h"
 
diff --git a/src/filter/facedetect/facedetect.cpp b/src/filter/facedetect/facedetect.cpp
index c27b458..697cef9 100644
--- a/src/filter/facedetect/facedetect.cpp
+++ b/src/filter/facedetect/facedetect.cpp
@@ -21,6 +21,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <opencv2/opencv.hpp>
+#include <opencv2/xobjdetect.hpp>
 #include "frei0r.hpp"
 #include "frei0r/math.h"