diff --git a/openair2/UTIL/MATH/oml.h b/openair2/UTIL/MATH/oml.h
index b34d47d5cc..e3aaa3619d 100644
--- a/openair2/UTIL/MATH/oml.h
+++ b/openair2/UTIL/MATH/oml.h
@@ -85,7 +85,7 @@ void init_seeds(int seed);
 * \note 
 * @ingroup  _oml
 */
-double wichman_hill() ;
+double wichman_hill(void) ;
 
 /*! \fn double uniform_rng();
 * \brief generates uniform random number with algo: wichman_hill / random() / Taus
@@ -94,7 +94,7 @@ double wichman_hill() ;
 * \note 
 * @ingroup  _oml
 */
-double uniform_rng();
+double uniform_rng(void);
 
 /*! \fn double uniform_dist(double min, double max);
 * \brief 
diff --git a/openair2/UTIL/OTG/otg_tx.h b/openair2/UTIL/OTG/otg_tx.h
index 725c959810..3ebeff2139 100644
--- a/openair2/UTIL/OTG/otg_tx.h
+++ b/openair2/UTIL/OTG/otg_tx.h
@@ -166,7 +166,7 @@ int adjust_size(int size);
 */
 void header_size_gen(int src, int dst, int application);
 
-void init_predef_multicast_traffic();
+void init_predef_multicast_traffic(void);
 
 /*! \fn void init_predef_traffic();
 * \brief initialise OTG with predifined value for pre-configured traffic: cbr, openarena,etc.