diff --git a/eo/src/eo b/eo/src/eo
index cd28e8489..cb05a8988 100644
--- a/eo/src/eo
+++ b/eo/src/eo
@@ -38,6 +38,7 @@
 #include <eoPrintable.h>
 #include <eoPersistent.h>
 #include <eoScalarFitness.h>
+#include <eoDualFitness.h>
 #include <EO.h>
 
 #include <utils/rnd_generators.h>