diff --git a/definitions/mars/grib.mmsa.em.def b/definitions/mars/grib.mmsa.em.def
index a4e6f175f..36ac9adc5 100644
--- a/definitions/mars/grib.mmsa.em.def
+++ b/definitions/mars/grib.mmsa.em.def
@@ -10,3 +10,6 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci")) {
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }
+
diff --git a/definitions/mars/grib.mmsa.fcmean.def b/definitions/mars/grib.mmsa.fcmean.def
index 213517b04..3b7f185b3 100644
--- a/definitions/mars/grib.mmsa.fcmean.def
+++ b/definitions/mars/grib.mmsa.fcmean.def
@@ -12,3 +12,6 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci")) {
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }
+
diff --git a/definitions/mars/grib.msmm.em.def b/definitions/mars/grib.msmm.em.def
index 663003e8e..86376c834 100644
--- a/definitions/mars/grib.msmm.em.def
+++ b/definitions/mars/grib.msmm.em.def
@@ -15,3 +15,6 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci")) {
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }
+
diff --git a/definitions/mars/grib.msmm.fcmax.def b/definitions/mars/grib.msmm.fcmax.def
index b548cbdc0..b64b923a1 100644
--- a/definitions/mars/grib.msmm.fcmax.def
+++ b/definitions/mars/grib.msmm.fcmax.def
@@ -16,3 +16,6 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci")) {
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }
+
diff --git a/definitions/mars/grib.msmm.fcmin.def b/definitions/mars/grib.msmm.fcmin.def
index c052e512e..158383e2c 100644
--- a/definitions/mars/grib.msmm.fcmin.def
+++ b/definitions/mars/grib.msmm.fcmin.def
@@ -16,3 +16,5 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci")) {
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }
diff --git a/definitions/mars/grib.msmm.fcstdev.def b/definitions/mars/grib.msmm.fcstdev.def
index 20b330ba3..3a563515b 100644
--- a/definitions/mars/grib.msmm.fcstdev.def
+++ b/definitions/mars/grib.msmm.fcstdev.def
@@ -17,3 +17,5 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci")) {
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }
diff --git a/definitions/mars/grib.msmm.hcmean.def b/definitions/mars/grib.msmm.hcmean.def
index 6e1de7002..8fc0cda27 100644
--- a/definitions/mars/grib.msmm.hcmean.def
+++ b/definitions/mars/grib.msmm.hcmean.def
@@ -15,3 +15,5 @@ if (centre == 80 && subCentre == 98 && (class is "c3" || class is "ci" (class is
   constant cnmc_cmcc = 'cmcc';
   alias mars.origin = cnmc_cmcc;
 }
+
+if (class is "ci") { unalias mars.method; }