diff --git a/example/particle-filter/pf-nonlinear-complex-example.cpp b/example/particle-filter/pf-nonlinear-complex-example.cpp
index bc6c30a0b4..1c9c5da090 100644
--- a/example/particle-filter/pf-nonlinear-complex-example.cpp
+++ b/example/particle-filter/pf-nonlinear-complex-example.cpp
@@ -74,6 +74,8 @@
   the interval \f$[- \pi ; \pi ]\f$ .
 */
 
+#include <iostream>
+
 // ViSP includes
 #include <visp3/core/vpConfig.h>
 #include <visp3/core/vpColVector.h>
diff --git a/example/particle-filter/pf-nonlinear-example.cpp b/example/particle-filter/pf-nonlinear-example.cpp
index d4784754bd..8e90acfbac 100644
--- a/example/particle-filter/pf-nonlinear-example.cpp
+++ b/example/particle-filter/pf-nonlinear-example.cpp
@@ -64,6 +64,8 @@
   not perfect.
 */
 
+#include <iostream>
+
 // ViSP includes
 #include <visp3/core/vpConfig.h>
 #include <visp3/core/vpGaussRand.h>