diff --git a/src/SURFEX/blowsnw_velgrav1d.F90 b/src/SURFEX/blowsnw_velgrav1d.F90
index d5bc2a19dc9101dfaec68727b9cda5e760fc5dd0..d44b7a3fb2f0e93400100e9e1d7d1576611dfc3a 100644
--- a/src/SURFEX/blowsnw_velgrav1d.F90
+++ b/src/SURFEX/blowsnw_velgrav1d.F90
@@ -43,6 +43,7 @@ USE MODD_BLOWSNW_SURF
 USE MODD_CSTS
 
 USE MODI_GAMMA_INC_LOW
+USE MODI_GAMMA_SURF
 
 USE MODE_BLOWSNW_SEDIM_LKT1D
 
@@ -90,7 +91,7 @@ REAL(KIND=JPRB) :: ZHOOK_HANDLE
 IF (LHOOK) CALL DR_HOOK('BLOWSNW_VELGRAV1D',0,ZHOOK_HANDLE)
 
 ZDELTAR = 1e-6 
-ZGAM      = GAMMA(XEMIALPHA_SNW)
+ZGAM      = GAMMA_SURF(XEMIALPHA_SNW)
 ILAYER=SIZE(PTA,2)
 
 ! Sutherland's equation for kinematic viscosity
@@ -112,9 +113,9 @@ IF(CSNOW_SEDIM=='TABC')  THEN
 
 ELSE IF(CSNOW_SEDIM=='MITC') THEN  ! Sedimentation following Mitchell (1996)
 
-  ZGAMB     = GAMMA(XEMIALPHA_SNW+3)
-  ZGAM_BM3  = GAMMA(3*XBM3-1+XEMIALPHA_SNW)
-  ZGAM_BM3B = GAMMA(3*XBM3+2+XEMIALPHA_SNW)
+  ZGAMB     = GAMMA_SURF(XEMIALPHA_SNW+3)
+  ZGAM_BM3  = GAMMA_SURF(3*XBM3-1+XEMIALPHA_SNW)
+  ZGAM_BM3B = GAMMA_SURF(3*XBM3+2+XEMIALPHA_SNW)
 
   ! Compute limit radius for integration of Mitchell's formulation
   ZR1(:,:)=RLIM(ZMU,PRHODREF,XBESTL_1)
diff --git a/src/SURFEX/gamma_inc_low.F90 b/src/SURFEX/gamma_inc_low.F90
index 1329e2ce71b7a245cfbddc72831d05b6a78aad31..ed5d094281b9f66f81547de5d2a8fea0108071a2 100644
--- a/src/SURFEX/gamma_inc_low.F90
+++ b/src/SURFEX/gamma_inc_low.F90
@@ -60,7 +60,7 @@ END MODULE MODI_GAMMA_INC_LOW
 !*       0. DECLARATIONS
 !           ------------
 !
-USE MODI_GAMMA
+USE MODI_GAMMA_SURF
 !
 IMPLICIT NONE
 !
@@ -124,7 +124,7 @@ ZC(4) = ZS(1) + ZS(2)/PA + ZS(3)/PA**2 + ZS(4)/PA**3 + ZS(5)/PA**4
 ZWORK = 0.5+0.5*TANH(ZC(2)*(PX-ZC(3)))
 
 PGAMMA_INC_LOW = EXP(-PX)* PX**PA * (1./PA +ZC(1)*PX/(PA*(PA+1.))+(ZC(1)*PX)**2/(PA*(PA+1.)*(PA+2.))) &
-                            * (1.-ZWORK) + GAMMA(PA)*ZWORK*(1.-ZC(4)**(-PX)) 
+                            * (1.-ZWORK) + GAMMA_SURF(PA)*ZWORK*(1.-ZC(4)**(-PX))
 RETURN
 !
 END FUNCTION GAMMA_INC_LOW
diff --git a/src/SURFEX/gamma.F90 b/src/SURFEX/gamma_surf.F90
similarity index 88%
rename from src/SURFEX/gamma.F90
rename to src/SURFEX/gamma_surf.F90
index cd7e04fbd7df5d80dd5e439b691f0f512197c981..e61ea735ae55cee97cff73b8bf7e893b9ab3937d 100644
--- a/src/SURFEX/gamma.F90
+++ b/src/SURFEX/gamma_surf.F90
@@ -1,25 +1,25 @@
-!MNH_LIC Copyright 1994-2014 CNRS, Meteo-France and Universite Paul Sabatier
+!MNH_LIC Copyright 1995-2018 CNRS, Meteo-France and Universite Paul Sabatier
 !MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
-!MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt  
+!MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 !MNH_LIC for details. version 1.
 !########################
-        MODULE MODI_GAMMA
+        MODULE MODI_GAMMA_SURF
 !########################
 !
-INTERFACE GAMMA
+INTERFACE GAMMA_SURF
 !
-FUNCTION GAMMA_X0D(PX)  RESULT(PGAMMA)
+FUNCTION GAMMA_SURF_X0D(PX)  RESULT(PGAMMA)
 REAL, INTENT(IN)                                  :: PX
 REAL                                              :: PGAMMA
-END FUNCTION GAMMA_X0D
+END FUNCTION GAMMA_SURF_X0D
 !
-FUNCTION GAMMA_X1D(PX)  RESULT(PGAMMA)
+FUNCTION GAMMA_SURF_X1D(PX)  RESULT(PGAMMA)
 REAL, DIMENSION(:), INTENT(IN)                    :: PX
 REAL, DIMENSION(SIZE(PX))                         :: PGAMMA
-END FUNCTION GAMMA_X1D
+END FUNCTION GAMMA_SURF_X1D
 !
 END INTERFACE
-END MODULE MODI_GAMMA
+END MODULE MODI_GAMMA_SURF
 !
 !--------------------------------------------------------------------------
 !
@@ -28,7 +28,7 @@ END MODULE MODI_GAMMA
 ! 
 !
 !     ######################################
-      FUNCTION GAMMA_X0D(PX)  RESULT(PGAMMA)
+      FUNCTION GAMMA_SURF_X0D(PX)  RESULT(PGAMMA)
 !     ######################################
 !
 !
@@ -64,6 +64,7 @@ END MODULE MODI_GAMMA
 !!    -------------
 !!      Original     7/11/95
 !!      C. Barthe    9/11/09  add a function for 1D arguments
+!!      P. Wautelet  07/09/2018 rename function to prevent problems with MesoNH (duplicated)
 !
 !*       0. DECLARATIONS
 !           ------------
@@ -123,7 +124,7 @@ ELSE
 END IF
 RETURN
 !
-END FUNCTION GAMMA_X0D
+END FUNCTION GAMMA_SURF_X0D
 !
 !-------------------------------------------------------------------------------
 !
@@ -132,7 +133,7 @@ END FUNCTION GAMMA_X0D
 ! 
 !
 !     ######################################
-      FUNCTION GAMMA_X1D(PX)  RESULT(PGAMMA)
+      FUNCTION GAMMA_SURF_X1D(PX)  RESULT(PGAMMA)
 !     ######################################
 !
 !
@@ -167,6 +168,7 @@ END FUNCTION GAMMA_X0D
 !!    MODIFICATIONS
 !!    -------------
 !!      Original     7/11/95
+!!      P. Wautelet  07/09/2018 rename function to prevent problems with MesoNH (duplicated)
 !!
 !-------------------------------------------------------------------------------
 !
@@ -221,4 +223,4 @@ WHERE ( PX(:)<0.0 )
 END WHERE
 RETURN
 !
-END FUNCTION GAMMA_X1D
+END FUNCTION GAMMA_SURF_X1D