diff --git a/src/MNH/spectre.f90 b/src/MNH/spectre.f90
index 9e8ce25ab4dc1a35bcebef0488aadebf566d8a19..7f29c03fb1b9a659ecfb015a0596d8a53bcbdcf1 100644
--- a/src/MNH/spectre.f90
+++ b/src/MNH/spectre.f90
@@ -45,7 +45,7 @@ IMPLICIT NONE
 !*       0.1   declarations of local variables
 !
 CHARACTER (LEN=28), DIMENSION(1) :: YINIFILE      ! names of the INPUT FM-file
-CHARACTER (LEN=28)               :: YOUTFILE      ! names of the OUTPUT FM-file
+CHARACTER (LEN=50)               :: YOUTFILE      ! names of the OUTPUT FM-file
 INTEGER                          :: IRESP         ! return code in FM routines
 INTEGER                          :: ILUOUT0       ! Logical unit number for the output listing
 INTEGER                          :: ILUNAM        ! Logical unit numbers for the namelist file