Index: /LMDZ6/trunk/libf/dyn3d_common/infotrac.F90
===================================================================
--- /LMDZ6/trunk/libf/dyn3d_common/infotrac.F90	(revision 4121)
+++ /LMDZ6/trunk/libf/dyn3d_common/infotrac.F90	(revision 4122)
@@ -781,5 +781,7 @@
    IF(ANY(nb_iso (:) /= nb_iso (1))) CALL abort_gcm(modname, 'Phases must have same number of isotopes', 1)
    IF(ANY(nb_tiso(:) /= nb_tiso(1))) CALL abort_gcm(modname, 'Phases must have same number of tagging tracers', 1)
-   IF(ANY(nb_zone(:) /= nb_zone(1))) CALL abort_gcm(modname, 'Isotopes must have the same number of tagging tracers', 1)
+   IF(i%nzone >= 1) THEN
+      IF(ANY(nb_zone(:) /= nb_zone(1))) CALL abort_gcm(modname, 'Isotopes must have the same number of tagging tracers', 1)
+   END IF
 
    !--- Isotopic checking routines activation flag