diff --git a/src/MNH/read_field.f90 b/src/MNH/read_field.f90
index 8774371974618e33c0592ce46af6d4334355973b..00593e5415708626fd57a918fba957f323943fd7 100644
--- a/src/MNH/read_field.f90
+++ b/src/MNH/read_field.f90
@@ -660,7 +660,10 @@ IF (LIBM .AND. CPROGRAM=='MESONH') THEN
     NDIMS      = 3,         &
     LTIMEDEP   = .TRUE.     )
    !
-   CALL IO_Field_read(TPINIFILE,TZFIELD,PIBM_XMUT)
+   CALL IO_Field_read( TPINIFILE, TZFIELD, PIBM_XMUT, IRESP )
+   !
+  !If field not found (only available in restarts) => set to 0.
+   IF ( IRESP /= 0 ) PIBM_XMUT = 0.
    !
 ENDIF
 !
diff --git a/src/MNH/write_lfin.f90 b/src/MNH/write_lfin.f90
index 43e3f1e22a929e658dfeab027eb2e00883750b7f..5d6517151f1749475da0f4ed554eafcf22efb772 100644
--- a/src/MNH/write_lfin.f90
+++ b/src/MNH/write_lfin.f90
@@ -507,18 +507,20 @@ IF (LIBM .OR. LIBM_LSF) THEN
   !
   CALL IO_Field_write(TPFILE,TZFIELD,XIBM_LS(:,:,:,1))
   !
-  TZFIELD = TFIELDMETADATA( &
-    CMNHNAME   = 'XMUT',    &
-    CLONGNAME  = 'XMUT',    &
-    CSTDNAME   = '',        &
-    CUNITS     = 'm2 s-1',  &
-    CDIR       = 'XY',      &
-    NGRID      = 1,         &
-    NTYPE      = TYPEREAL,  &
-    NDIMS      = 3,         &
-    LTIMEDEP   = .TRUE.     )
-   !
-   CALL IO_Field_write(TPFILE,TZFIELD,XIBM_XMUT)
+  IF ( CPROGRAM == 'MESONH' ) THEN
+    TZFIELD = TFIELDMETADATA( &
+      CMNHNAME   = 'XMUT',    &
+      CLONGNAME  = 'XMUT',    &
+      CSTDNAME   = '',        &
+      CUNITS     = 'm2 s-1',  &
+      CDIR       = 'XY',      &
+      NGRID      = 1,         &
+      NTYPE      = TYPEREAL,  &
+      NDIMS      = 3,         &
+      LTIMEDEP   = .TRUE.     )
+    !
+    CALL IO_Field_write(TPFILE,TZFIELD,XIBM_XMUT)
+  END IF
    !
 ENDIF
 !