diff --git a/eo/src/eoOp.h b/eo/src/eoOp.h
index dbeb65b5..5f8e46ea 100644
--- a/eo/src/eoOp.h
+++ b/eo/src/eoOp.h
@@ -27,7 +27,7 @@
 #include <eoObject.h>
 #include <eoPrintable.h>
 #include <eoFunctor.h>
-
+#include <utils/eoRNG.h>
 /**
 \defgroup operators
 Genetic Operators are used for various purposes
diff --git a/eo/src/eoPop.h b/eo/src/eoPop.h
index 42f087aa..076921d3 100644
--- a/eo/src/eoPop.h
+++ b/eo/src/eoPop.h
@@ -33,6 +33,7 @@
 #include <eoOp.h> // for eoInit
 #include <eoPersistent.h>
 #include <eoInit.h>
+#include <utils/rnd_generators.h>  // for shuffle method
 
 /** Subpopulation: it is used to move parts of population
  from one algorithm to another and one population to another. It is safer