diff --git a/eo/src/eoRankMuSelect.h b/eo/src/eoRankMuSelect.h
index 8c22f124..6e0a737e 100644
--- a/eo/src/eoRankMuSelect.h
+++ b/eo/src/eoRankMuSelect.h
@@ -28,6 +28,8 @@ Authors:
 #ifndef _eoRankMuSelect_h
 #define _eoRankMuSelect_h
 
+#include "eoDetSelect.h"
+
 /** Selects the "Mu" bests individuals.
  *
  * Note: sorts the population before trucating it.